Under this head is included the greater proportion of those substances which are employed as the instruments of crime; for they are generally of easy access, require but little preparation, and are so destructive in small doses, and, at the same time, so little disgusting in flavour, as to furnish the assassin with the sure and secret means of destruction. Fortunately, however, for the ends of justice, such agents are pre-eminently the objects of successful analysis. In treating of the history of the individual substances derived from this kingdom, we shall consider, 1st. their external characters, such as form, colour, odour, taste, specific gravity; 2d. their chemical composition, and habitudes; 3d. the tests by which their presence may be recognised; 4th. the symptoms which they occasion; 5th. their physiological action; 6th. their different modes and forms of application; 7th. the lesions of structure they occasion; 8th. the phenomena presented on dissection.

Cl. 1. CORROSIVE POISONS.

ARSENIC.

The greek word ??se????? was employed by Dioscorides, and other writers of that period, to denote a particular mineral of a reddish colour, which Aristotle had already described by the name of sa?da?a??,^[214] and his disciple Theophrastus, by that of a??e?????. It was employed by the ancients both as a pigment and as a medicine, and appears to have been a compound of Sulphur, and a peculiar metal, to which the name of Arsenic is now exclusively applied. At what period this metal was first discovered seems very doubtful; and although a process for obtaining it is described in the Pharmacopoeia of Schroeder, published in 1649, yet its peculiar nature was examined, for the first time by Brandt, in 1733.

The metal, Arsenic, is distinguished by the following properties, viz.

It has a bluish-grey colour, not unlike that of steel, and a considerable lustre; its texture is grained, and sometimes scaly; its hardness not very considerable, but its fragility is so great that it falls to pieces under a moderate blow of the hammer, and admits of being easily reduced to a very fine powder; according to Bergman its specific gravity is 8·31. When cold, it emits no sensible odour, but if heated, it yields a strong alliaceous, or garlic-like smell, which is to be considered as the most characteristic of its properties. Its point of fusion is unknown, for it is the most volatile of all the metals, and sublimes, before it melts, at the temperature of 540° Fah., and if the process be conducted slowly in close vessels, the metallic sublimate will assume a tetrahedral^[215] form of crystallization; if the air be admitted, and the temperature still farther raised, it will burn with an obscure bluish flame.

Arsenic is extremely susceptible of oxidation, and, by mere exposure to the air, shortly loses its metallic lustre; and yet it may be kept under the surface of cold water, for any length of time without exhibiting the signs of oxidation, or solution; a covering of this fluid, or of alcohol, is therefore considered as affording the best means of preserving the metal in a state of integrity.

Arsenic is capable of combining with two proportions of oxygen, and of forming two definite compounds, which we shall hereafter consider under the title of Arsenious and Arsenic acids. The substance described by some authors as the black oxide of this metal would seem to be an indefinite mixture of the metal itself, and the arsenious acid.

Arsenic does not appear to possess any deleterious properties, but it is almost impossible to reduce the metal to powder, so as to adapt it for exhibition without its becoming oxidized. M. Renault therefore, in order to decide the question, had recourse to its alloys; and he found that Mispickel (an alloy of Arsenic and Iron), when given to the extent even of two drachms, scarcely produced any effect; a result which very satisfactorily accords with the conclusion drawn by Bayen, in his work on Tin, and which proves that the arsenic contained in that metal, need not excite the least alarm, since it exists in a metallic state. We have upon another occasion^[216] observed, that the vapours characterised by an alliaceous odour are probably less noxious than the arsenical fumes which are inodorous; and that the little injury experienced by workmen who solder silver filligree with an arsenical alloy, may probably depend upon the deoxidized state of its fumes.

ARSENIOUS ACID, or WHITE OXIDE OF ARSENIC.

This is justly considered as the most fatal of all mineral poisons, and is the one more frequently selected than any other, as the instrument of assassination and suicide; while its numerous applications in medicine and the arts, by making it an article of general and indiscriminate sale, have rendered it an accidental as well as criminal source of suffering and death.

It is seldom prepared by the chemist, since it exists in a native state, and is moreover procured abundantly and economically, during the extraction of the other metals from their ores.^[217] In the commercial world the substance is still known by the name of White Arsenic; and continues to be expressed in popular language, by the simple term Arsenic.

It generally occurs in the form of white compact masses, opaque on their exterior surface; transparent, and presenting a vitrified aspect in the interior. Its taste is acrid and corrosive, but not to a degree corresponding with its virulence. Specific gravity 3·7. When reduced to powder it bears a strong resemblance to refined sugar, for which it has sometimes been fatally mistaken, and with which it has been often mingled for criminal purposes. At the temperature of 383° Fah. it is volatilized, and is capable of crystallizing in tetrahedrons with truncated angles, or rather in octohedrons; by a strong heat, in close vessels, it is vitrified and becomes pellucid, and acquires the specific gravity 5·000^[218]; but when exposed to the air, it shortly returns to its former appearance. In the state of vapour it is quite inodorous, although the contrary is positively asserted in several chemical works of high authority, and it is stated to be characterised by a smell like that of garlic; the fact is, that the alliaceous or garlic-like smell is wholly confined to metallic arsenic in a state of vapour; and whenever the arsenious acid seems to yield such an odour, we may very confidently conclude that its decomposition has taken place, and that it has been reduced to its metallic state. Such a reduction will generally happen when it is projected upon ignited charcoal, or when heated in contact with those metallic bodies which readily unite with oxygen, such as Antimony, Zinc, &c. It is stated by Orfila and other writers, that if it be projected upon heated copper the alliaceous odour is evolved. This assertion is undoubtedly true, but the fact requires to be explained with more precision, or we may fall into an important error respecting it. The author has shewn by several experiments, already published in his Pharmacologia,^[219] that the phenomenon takes place only when the copper is in a state of ignition, at which temperature its affinity for oxygen enables it to reduce the arsenious acid, and consequently to develope the metallic odour. We have ascertained by repeated experiments that if a few grains of arsenious acid be heated on a plate of copper, by means of a spirit lamp or the blow-pipe, no odour is perceptible; for, in this case, the whole of the acid will be dissipated before the copper can acquire a temperature sufficiently exalted to deoxidize, and reduce it. If the arsenious acid be heated on a plate of zinc, the smell will not be evolved until the latter metal is in the state of fusion. If, instead of the foregoing surfaces, we employ in our experiments those of gold, silver, or platina, no alliaceous smell whatever is produced, at any temperature, provided every source of fallacy be carefully avoided; but it deserves particular notice, that the author has found the flame of the spirit lamp to be in itself, capable of decomposing the arsenious acid, in consequence, it is presumed, of the operation of its hydrogen;^[220] a fact which is very likely to betray the experimenter, as in the first instance it did the author, into a belief that the arsenious acid does actually yield the odour in question.

The term Arsenious acid was first bestowed upon this substance by Fourcroy, since it was found to possess many of the essential habitudes of an acid; as for instance, that of combining with the pure alkalies to saturation. It dissolves in water; but, according to Klaproth, although it requires for its solution 400 parts of that fluid, at the temperature of 60° Fah. it requires not more than 13, at 212°; and it moreover appears that if 100 parts of water be boiled on the arsenious acid, and suffered to cool, it will retain 3 grains in solution, and deposit the remainder in crystals. This fact shews the great importance of employing boiling water in every chemical examination of substances supposed to contain arsenic. It proves also that a fatal dose of the poisonous mineral may be very easily administered in any watery vehicle, a fact which was denied on the trial of Ogilvy and Nairne^[221] by Dr. James Scott, who deposed that “Arsenic would not dissolve in warm water, but almost instantly subside to the bottom of the vessel,” although, at the same time, he acknowledged that “if it were put into tea with milk and sugar, and stirred about, it might be suspended long enough to kill those who should drink the potion.” It is soluble in alcohol, and in fixed oils, the former taking up two per cent. By the addition of an alkali, an arsenite of great solubility will result, and a solution of extreme virulence may be thus effected. With lime-water arsenious acid produces a white precipitate of arsenite of lime, but which is soluble in an excess of the acid. With magnesia it also forms a very soluble, and extremely active, arsenite.

Symptoms of Poisoning by the Arsenious Acid.

Hahnemann, in his work on Arsenic, proposes a classification of its effects founded on their relative duration and violence, and which it is our intention to adopt on the present occasion, without any other alteration than that of reversing the order of the classes.

Poisoning by Arsenic may accordingly be considered as admitting of three degrees of intensity, viz. 1st. Where the case, although attended with dangerous symptoms, does not terminate fatally. 2d. Where death does not follow until after a lapse of twenty-four hours. 3d. Where death takes place within twenty-four hours after the exhibition of the poison.

1. Symptoms of the first and lowest degree. In the slighter cases in which the operation of arsenic is recorded as producing poisonous effects, the symptoms were, uneasiness of the prÆcordia; cholics; thickness, redness, and stiffness of the palpebrÆ; soreness of the gums; ptyalism; itching over the surface of the body, sometimes attended with a slight eruption; restlessness; cough; head-ache; strangury, and ardor urinÆ. Where the dose of poison has been somewhat greater, although still inadequate to the destruction of life, violent vomiting is commonly the first symptom, preceded in some instances with a sense of heat and dryness in the fauces; in such cases where the vomiting has very shortly succeeded the ingestion of the Arsenic, and the stomach has at the same time been filled with food, the patient may owe his escape to the poison being discharged before it had time to act. Morgagni relates a case of poisoning at an Italian feast, where the dessert was intentionally sprinkled with Arsenic instead of flour; those who had previously eaten but little speedily perished, but those who had eaten heartily were saved by vomiting. Although in this degree of poisoning the life of the patient may be spared, yet a variety of consecutive symptoms may continue to harrass him for a longer or shorter period, such as indigestion, debility, partial paralysis, and epilepsy. The history^[222] of the cases of Mr. Turner and his family, of Chancery lane, for the poisoning of whom Eliza Fenning was executed, will afford a striking illustration of this fact. The hair of the head has also been observed, in some cases, to fall off. Dr. Male is also of opinion that the long protracted and injudicious use of this mineral, as a medicine, will induce exostosis and caries of the bones.

2. Symptoms of the second degree. In this case where the patient lives two or three days, or perhaps longer, as in the case of William Mitchell above described (p. 190), the earliest symptoms are heat and thirst, or vomiting, and inexpressible uneasiness and anxiety, the former of which is less frequently observed than the two latter; purging, or sometimes a repeated but ineffectual desire to go to stool; wandering pains; quick, but feeble pulse; head-ache; distended and painful abdomen; priapism; towards the close of the scene the patient often becomes more tranquil and is inclined to sleep, although, in some instances, the pains, attended with convulsions, continue to the latest moments. In general, death takes place suddenly. In cases where the effects of the poison are not immediately fatal, we must necessarily expect the occurrence of many phenomena, indicative of the re-action of the system, and which will be better illustrated by a reference to the history of individual cases, such for instance, as those of William Mitchell, (p. 190) and Mr. Blandy, (Appendix) than by any general description which can be given in this place. It is also worthy remark that in such cases, from the length of time, there will necessarily occur a greater opportunity for the co-operation of other contingent causes, whether they be connected with previously existing diseases, or the action of remedies; and the intelligent practitioner will not neglect to appreciate their influence in modifying the character of each particular case. There are besides symptoms highly characteristic when they do arise, but which are of comparatively rare occurrence, such as the ulcerated condition of the fundament, as in the case of Mr. Blandy, and the inflamed eyes and state of the mucous membranes, in that of William Mitchell.

3. Symptoms of the third and highest degree. Soon after a large dose of Arsenic has been swallowed, an austere taste, and a sense of heat and constriction of the pharynx and oesophagus are perceived; in a short period excruciating pains in the stomach and bowels, accompanied with vomiting of the most violent character, the matter voided being generally of a brown colour, and not unfrequently mixed with blood; with these symptoms are conjoined an inexpressible anxiety about the prÆcordia, and frequent faintings; the stomach at the same time acquires such a high degree of irritability, as to reject the mildest fluids. The alvine discharges now become frequent and painful, and consist of dark and extremely foetid matter, frequently mixed with blood. The thirst is unquenchable, and the heat of the surface becomes extreme. The pulse is small, frequent, and irregular; palpitations of the heart, violent cramps in the legs, sometimes a painful strangury and bloody micturition ensue. The powers of life begin to fail, respiration becomes laborious, cold sweats break out, hiccup occurs, the countenance assumes a singular character of anxiety and distress, a livid circle appears around the eyes, the pulse is imperceptible, the body swells and sometimes becomes covered with a species of miliary eruption, or with dark purple spots. In some cases convulsions ensue, but delirium, or loss of reason, is very rarely the consequence of this species of poisoning, and the unfortunate sufferer is conscious until a few moments before the termination of his existence. Such are the general symptoms, but it is rare to see them all united in the same case; sometimes the greater part of them are absent. M. Chaussier reports the case of a robust middle aged man, who swallowed a quantity of arsenious acid in large lumps, and died without discovering any other symptom than slight syncope; other cases are related where only vomiting and purging^[223] have been observed, and the symptoms have been mistaken for those of cholera spontanea.

The practitioner is therefore not to withhold his belief in a case of poisoning, on account of the absence of several of those symptoms which are enumerated in systematic works on Toxicology.

It is only by the study of individual cases, that he can learn to appreciate the just value of those pathognomonic combinations which afford the least exceptionable evidence upon such occasions.

The different modes of Poisoning by Arsenious Acid.

It has been proved by numerous experiments that the life of an animal may be destroyed with equal certainty by arsenious acid, whether it be internally administered, or externally applied to abraded surfaces, sores, or bleeding wounds; and it has been, moreover, shewn, that in either instance the symptoms will be analogous, except in the latter case they will often be more rapid in their course.

Lionardo di Capoa relates the case of a child killed by the violent vomiting and purging arising from a slight wound made in the head by a comb, wet with oil in which arsenic had been infused for the purpose of killing vermin; and we have numerous instances on record, where the application of arsenical cerates and ointments has been followed by violent and dangerous symptoms. We also learn from the different historians of the Plague of London, that the arsenical amulets which were worn, as preservatives, on that occasion, were sometimes attended with deleterious consequences; Crato^[224] observed an ulcer of the breast produced by them. Verzascha, violent pains and syncope. Diemerbroeck,^[225] and Dr. Hodges,^[226] death itself. Amongst the foreign authors who have related cases of poisoning by the external application of arsenic we may mention Desgranges,^[227] who records the history of a chambermaid, poisoned by having rubbed her head with an arsenical ointment for the purpose of destroying vermin; and Roux,^[228] who confessed to have killed a girl of eighteen by an application of the “PÂte Arsenicale” to a cancerous breast. M. Renault has also given us the results of his experiments upon Arsenic when applied externally to dogs; when the skin was sound, it excited a pustular eruption without inflammation; but, when the skin was broken, more serious effects followed, both general and local, and in some cases death.^[229]. In an experiment performed by Mr. Hunter, and Mr. Home, in which arsenic was applied to a wound in a dog, the animal died in twenty-four hours, and the stomach was found to be considerably inflamed. Mr. Brodie repeated the experiment several times, always with the precaution of tying a bandage, to prevent the animal licking the wound; the results were uniform; the stomach was, in every case, not only more violently, but more rapidly, inflamed, than when the poison had been internally administered, and it even preceded any inflammatory appearance of the wound. In the Journal de Medecine, the following case is related of a woman who was killed by her husband having insinuated powdered arsenic into the vagina,^[230] at the moment of enjoying the conjugal rites. “A woman at Leneux, departement de l’Ourthe, aged forty, having died after a short illness, attended with considerable tumefaction of the genital parts, uterine hemorrhage, vomiting, and purging, the body was inspected by order of the mayor, when the surgeons reported that they found the vulva in a state of gangrene, the abdomen much distended with air, and the intestines inflamed and gangrenous. The culprit was arrested, convicted, and executed.” In the Acts of the Society of Copenhagen, a similar crime stands recorded, and which was also committed by a peasant; in this latter case, although some small pieces of arsenic were found within the vagina, yet some doubts arose respecting the possibility of such a species of poisoning, and the magistrates accordingly consulted the College of Medicine of Copenhagen, who decided the question in the affirmative, having first instituted a series of experiments upon horses.

Death may also be produced by the introduction of arsenic into the rectum; it is said that Sir Thomas Overbury, after the failure of the various poisons^[231] that were administered to him, was at last despatched by an arsenical glyster.

With respect to the quantity of arsenic required for the production of such effects it is difficult to offer a decided opinion, as its operation must in every case be liable to contingency; but a very few grains are in general amply sufficient.

It had long been supposed that arsenic occasioned death by inflaming the stomach; but Mr. Brodie^[232] has very satisfactorily proved, that its influence arises from its being absorbed, and that it must be regarded as a vital rather than as a chemical agent, and as having a constitutional, not a local mode of operation.

In the first place, he has in many instances found the inflammation of the stomach so slight,^[233] that on a superficial examination it might have been easily overlooked; and in most of his experiments with arsenic, death took place in too short a period to be considered as the mere effect of inflammation. In the next place we have already shewn that in whatever manner the poison is applied, whether externally to a wound, or internally, to the alimentary canal, the same inflammatory appearance will be visible in the stomach; a fact which can only be explained by admitting that the poison is absorbed, and that it acts upon these organs through the medium of the circulation; it acts at the same time upon the brain, and heart, but with different degrees of force in different cases; so that it is sometimes difficult to ascertain which of these organs is the first to fail in its functions. According then to these experiments and observations, inflammation of the alimentary canal is not to be considered as the general cause of death in poisoning by arsenic; and yet cases will occur, where the local affection may prove fatal, the animal having survived the effects produced on the organs more immediately subservient to life, as the brain and heart. Mr. Henry Earle communicated to Mr. Brodie a case highly illustrative of this fact, which occurred in St. Bartholomew’s hospital; a woman had taken arsenic, and having recovered from the alarming symptoms which first occurred, died at the end of four or five days, when upon dissection, there appeared extensive ulcerations of the stomach and bowels. This then was evidently a case of “Consecutive” poisoning.

The dissertation of Dr. Jaeger, to which we have before alluded, contains the result of a very extensive series of experiments, in illustration of the physiological action of the arsenic. He diligently examined its effects upon all classes of organized beings, as well of the vegetable as of the animal kingdoms. The general conclusions which he has drawn from his experiments on vegetables are, that arsenic is in most cases a rapidly destructive poison to them, with the exception perhaps of a few of the simplest forms of existence;^[234] and that their death was induced by means of the gradual absorption and distribution of the poison by the vessels and cellular membrane, so that the parts died in succession, as the particles of the poison reached them. Dr. Jaegar also found that arsenic was a quick and destructive poison to animals, and that death was preceded, in every instance, from the infusory animalcula up to man, by inordinate motions; and that the secretion was most remarkably increased from the mucous membranes. His experiments also proved that arsenic exerted the most powerful effects, when it was injected into the veins, or applied to a bleeding wound; next, when it was introduced into the stomach; but less so, when injected into the large intestines, which have fewer absorbing vessels.^[235]

Organic Lesions, discovered on Dissection.

The examination of the bodies of persons poisoned by arsenic, must not be expected to furnish constant and uniform results, since they will be found to vary very considerably in different cases. As we have already considered the value of accelerated and retarded putrefaction, as an indication of poisoning, we shall at once proceed to the description of the morbid phenomena which are presented by the internal organs on dissection. The stomach and intestines are the parts in which we may expect to find the most decided marks of the ravages from arsenic. The former viscus will be found more or less inflamed; in some instances, the dusky redness will appear in patches, interspersed with points and streaks of a brighter hue; the villous coat of the stomach will be almost always softened, and, as if macerated, can be easily rubbed off in pieces with the fingers from the coats beneath; actual ulceration and sloughing are, according to the observations of Mr. Brodie, never found unless where death is late in taking place, in which case extensive ulceration of all the coats, amounting to actual perforation, may be expected to happen. This statement agrees with the observation of Ruysch, who says that where there had been sufficient time, he found the stomach ulcerated in those who had died from the effects of arsenic, but that if death supervened earlier, he only discovered bloody points, distant from each other, throughout the viscus. On the subject of sloughs upon such occasions, our enlightened author remarks, that anatomists have often been betrayed into a fallacy respecting their true nature; on opening the stomach of a dog which had taken a large quantity of arsenic, Mr. Brodie observed a dark brown spot about an inch in diameter, having all the appearance of a slough; on a closer examination, however, it appeared that this spot was no other than a very thin layer of coagulated blood, of a dark colour, and adhering very firmly to the surface of the mucous membrane, and having a few particles of arsenic entangled in it. He states that he has at several times observed a similar appearance but occupying a less extent of surface; and he informs us that, in the Hunterian museum, there is a human stomach, which was preserved for the sake of exhibiting what was considered a slough, produced by the action of arsenic; but that, on examining the preparation carefully, the dark coloured spot was discovered to be simply a layer of coagulated blood, similar to that before described. Dr. Baillie and Dr. Yelloly have found the stomach thickened in several parts, as if by coaguable lymph, and in one case the thickening of the coats was the only alteration of structure observable; and M. Renault relates a case, where the arsenic was taken in large pieces, which produced no other effect than slight syncope on the approach of death; and that, upon opening the body, the arsenic was found in the state it was swallowed, but there was neither inflammation nor erosion of the stomach. Where the arsenic has been swallowed in substance, it will be generally found attached to the membrane of the stomach by a peculiar glairy fluid; if the poison should have been administered in solution, the same organic lesions will be discovered, but the presence of the arsenic in the stomach can scarcely be expected, although the contents of the viscus, as well as all the matter ejected from the body before death, must be carefully examined by a chemical process to be hereafter described. The duodenum, like the stomach, generally affords evidence of the same inflamed and disorganized condition; and the whole track of the intestinal canal will be found more or less affected, according to the quantity of arsenic that has been administered, the period of time which has elapsed before death, and other circumstances which have been already enumerated as capable of modifying the action of this destructive substance. It however deserves notice that in many cases the rectum appears to be more affected than the other intestines; Dr. Male^[236] states, that he has frequently found it abraded and ulcerated, and even more inflamed than the stomach itself; Mr. Brodie likewise observed, in his physiological experiments upon this substance, that the inflammation produced by it was greatest in the stomach and the rectum. Dr. Baillie has recorded several instances where a mortification of the rectum followed as an effect of this poison; and in the case of Mr. Blandy, detailed in the Appendix, p. 237, Dr. Addington stated, that the extremity of the rectum was extremely painful, and surrounded by excoriations and ulcers.

Mr. Brodie has stated, in the paper to which we have so often alluded, that the organic lesions occasioned by arsenic are confined to the stomach and intestines, and that he never found any appearance of inflammation in the pharynx or oesophagus. This statement, however, is at variance with a great weight of authority; we have ourselves witnessed cases in which dissection has demonstrated extensive inflammation in these parts; indeed it would appear, that this poison acts more particularly on the mucous membranes; and it is reasonable therefore to conclude, that those with which it comes in actual contact will not escape its virulence. The serous membranes which receive less blood, and more lymphatics, are necessarily less affected by it.

In the case of William Mitchell, as related at page 188, the patient complained of soreness of the eyes, heat and uneasiness in the mouth and throat; and the surgeon observed the membrane on the palate and uvula to be detached; so in that, again, of Mr. Blandy, Dr. Addington found on inspection that “his tongue was swelled, and his throat inflamed and excoriated; his lips, especially the upper one, dry and rough, and having angry pimples on them; the inside of his nostrils in the same condition, and his eyes a little blood shot.” (Append. l. c.). In the celebrated Scotch case of Oglivy and Nairne (see page 184) Peter Meik, surgeon of Alyth, deposed, that, upon inspecting the body four or five days afterwards, he found “the tongue swelled beyond its natural size, and cleaving to the roof of the mouth, which he had never observed after a natural death.” Many more instances might be adduced to shew that the fauces, pharynx, and oesophagus are very frequently inflamed and excoriated by the ingestion of arsenic. Mortification of the pudenda^[237] has been said to be an effect peculiar to the action of arsenic; certain it is that in males, priapism is sometimes a symptom of this poison, and the penis is found swollen and red after death, as was observed in the case of William Mitchell (p. 190). The scrotum was also enlarged and of a dark colour. We have been long aware that persons exposed to the fumes of arsenic, or accustomed to handle any of its preparations, have been liable to a peculiar affection of these parts, but we have generally explained the fact by supposing that the poison had in such cases, been locally applied to them. The author has been lately informed by his friend Mr. Parkes, that several persons in his establishment were thus attacked, during the time they were engaged in preparing an arsenical solution, as a dye for the calico printers; and we have stated on another occasion,^[238] that the smelters and workmen engaged in the copper works, and tin burning houses of Cornwall, are occasionally affected with a cancerous disease in the scrotum, somewhat similar to that which infests chimney sweepers. It is also singular that Stahl, in describing the putrescent tendency in the bodies of those who die from this poison, mentions in particular the gangrenous appearances of the parts of generation. The other organs of the body do not exhibit any particular appearances, which ought to be regarded as characteristic of death by arsenic; we must necessarily expect to find the traces of morbid action, especially where life has been unusually protracted; and the serous effusions found in the body of William Mitchell, are to be referred to such a cause.

Mr. Brodie has stated that, in animals killed by arsenic, the blood is usually found fluid in the heart and vessels after death; this agrees with the observation of Ruysch, who says that he never found the blood coagulated in the human body, after death occasioned by this poison; as well as with that of Dr. Jaeger, who describes the cavities of the heart, especially of the right side, to be, upon these occasions, turgid with blood, but that coagula are very seldom found in them.

A question, of a very considerable importance in a forensic point of view, has arisen with respect to the means, by which we may distinguish whether arsenic, found in the body, had been introduced into the digestive canal during life, or after death. In general, this fact is placed beyond suspicion by the testimony of those to whose care the body had been confided, previous to dissection. But cases have occurred where a poisonous substance has been introduced into the rectum of a dead body, with the diabolical intention of accusing an innocent person of having been the perpetrator of the poisoning. We are not aware of any English case of this kind, but M. Orfila states that in the proceedings of the Criminal Court of Stockholm such a case stands recorded. Fortunately there would not be much difficulty in detecting the crime; for were the arsenic applied to the rectum after death, the change of structure would not extend beyond the part in actual contact with it, but would be distinctly separated from the rest of the intestine by a well defined line of demarcation, which can never happen where the arsenic has acted during life; for, in this latter case, the transition from the diseased to the healthy structure will be gradual, and the limits of each imperceptible.

Before we conclude our observations upon the organic lesions occasioned by arsenic, we may caution the anatomist not to confound the red or violet colour which characterises inflammation, with that which has been occasionally found to arise from the ingestion of certain coloured drinks. The following case related by FoderÉ, and cited by Orfila, may serve to illustrate this subject. “A private person of ChÂlons sur-Marne, who was in a state of convalescence from a disease under which he had laboured, took a slight purgative, and died very shortly afterwards. He was believed to have been poisoned through some error in the medicine, and in order to be assured of this, the body was opened. The oesophagus and stomach were found to be red, and in certain places livid, as if in a state of gangrene. These appearances at first induced a belief that the deceased had died from poison; but M. Varnier, a physician of ChÂlons, concluded from the appearances, that death was the consequence of the disease, and that the apparent convalescence was only an insidious respite. It became therefore necessary to give some account of the state of the oesophagus and stomach; and having learnt that the deceased was in the habit of using a strong infusion of red poppies, the idea immediately struck him that the extraordinary colour of these organs might possibly depend on this infusion. In order to determine the validity of this explanation, he caused a dog to swallow, several times, a similar infusion; when upon opening its body, he discovered that the corresponding parts of this animal had assumed the same colour as had been observed in the stomach of the deceased above-mentioned, and, moreover, that this violet red colour was so firmly fixed that it resisted the action of repeated washings.” Tincture of Cardamoms will also be liable to occasion a coloured appearance in the stomach, as described in Mr. Stanley’s case of the death of a woman by a dose of opium.^[239]

Of the Chemical Processes, by which the presence of Arsenious Acid may be detected.

This poison may either be submitted to the judicial physician for examination, in its solid form, or in that of solution; and in this latter state it may be mixed with various alimentary substances, whose presence will necessarily embarrass the inexperienced operator, and multiply the apparent difficulties of his task. It becomes our duty, therefore, upon this occasion, to enter very fully and minutely into the history of the various processes, which have been proposed for the solution of the important problem under consideration; to appreciate the relative value of each, and to point out the sources of fallacy and failure, to which they are severally exposed.

Such a review of the subject would, moreover, appear to be essentially necessary at the present period, since the evidence, lately delivered on an extraordinary trial,^[240] has, to a certain extent, very unjustly shaken the public confidence in the tests of chemistry. We shall therefore proceed to consider the processes which are calculated to lead to the detection of Arsenic, in relation to the different circumstances under which it may be presented for investigation, viz. 1, In a solid form; 2, In the simple state of solution; and 3, In the state of combination with various alimentary substances.

1. The Arsenic is in a solid form. This is the most simple case which can occur, and the experiments by which its presence is to be demonstrated, will constitute the basis of the inquiry, which we shall be hereafter called upon to institute, for the detection of the same substance under other circumstances of mixture and combination.

The order of succession to be observed in the different experiments which we are about to describe, must, in a great measure, be regulated by the quantity of the material to be submitted to examination. Should it be small, it will be prudent to reserve the process of metallization, by which a considerable loss must necessarily arise, until we have submitted it to the various re-agents which are calculated to afford indications of its nature. If, on the contrary, the quantity of the substance exceed two or three grains, it will be adviseable to proceed in its examination by the following processes, reserving a portion for future analysis.

A. By its reduction to a metallic state. Mix a portion of the suspected substance in powder, with three times its weight of black flux^[241]; put the mixture into a thin glass tube, about eight inches in length, and a quarter of an inch in diameter, and which is hermetically sealed^[242] at one end. Should any of the powder adhere to the sides of the tube it must be carefully brushed off with a feather, so that the inner surface of its upper part may be perfectly clean and dry. The closed end of the tube, by way of security, may be thinly coated with a mixture of pipe-clay and sand^[243]; but this operation is not absolutely necessary. The open extremity of the tube is to be loosely plugged with a piece of paper. The coated end must now be submitted to the action of heat, by placing it in a chaffing dish of red hot coals, for ten minutes, or a quarter of an hour; when, if our supposition respecting the nature of the substance has been correct, metallic arsenic will sublime, and be found lining the upper part of the tube with a brilliant metallic crust. The glass tube, when cold, may be separated from its sealed end by the action of a file, which will enable us to collect and examine the metallic sublimate. If a portion of this brilliant matter be laid on heated iron, it will indicate its nature by exhaling in dense fumes, having a powerful smell of garlic. Another portion should be reserved for future experiments.

This method of detecting the presence of Arsenious acid has been considered the most decisive, and indeed the only unexceptionable one, but of this we shall speak hereafter; at present we have only to observe, that it is very far from being a minute test, for Dr. Bostock^[244] confesses that where less than three-fourths of a grain were used, he could not say that the metallic crust was clearly perceptible; and Dr. Black^[245] appears to have considered that one grain was the smallest quantity which could be distinctly recognised by such a process.

Chemists were formerly^[246] in the habit of at once projecting any substance, supposed to be Arsenic, on some burning body, in order to develope the alliaceous odour; we have accidentally stumbled upon an instance of this kind, in the fourth volume of the London Medical and Physical Journal, which may serve as an illustration; it is a case communicated by F. Thackeray, Esq. of a child poisoned by arsenic, in which the author says, “the inner surface of the stomach was very red, and was studded throughout with a white powder, which when exposed to the flame of a candle, yielded fumes, and a garlic odour was emitted, proving it was arsenic; of which there can be no doubt, as the girl afterwards confessed that she had given arsenic to the infant.”

After the facts we have offered with respect to the alliaceous odour of arsenical fumes, it is only necessary to state, in this place, that such a test, when conducted in the manner just related, must be considered as extremely equivocal.

Another method of identifying “White Arsenic,” by metallization, is to form at the moment of its reduction, an alloy with copper, which may be easily effected in the following manner: Mix the suspected powder with black flux, as in the former experiment, and place the mixture between two polished plates of copper; bind them tightly together by iron wire, and expose them to a low red heat; if the included substance contain arsenic, a silvery white stain will be left on the surface of the copper, which is an alloy of the two metals. In this, as in the former experiment, the presence of an alkali in the flux is essential, since it forms immediately an arsenite of potass, and thereby fixes the arsenious acid, and prevents it from being volatilized before the temperature is sufficiently high to enable the charcoal to decompose it; we therefore differ with Dr. Bostock, when he states that powdered charcoal may be substituted for the black flux.

The property of whitening copper is regarded as a very satisfactory test of the presence of arsenic; but Dr. Bostock has pointed out some circumstances attending it, which we shall here enumerate for the instruction and satisfaction of the less experienced operator. “It may be necessary,” says he, “in the first place, to describe the phenomena that take place when copper is heated according to the process that is described above, but without the addition of the arsenic. Two copper disks, of nearly an inch and a half in diameter, scoured bright with sand, had one grain of powdered charcoal, made into a paste with oil, placed between them; they were bound together with an iron wire, and then kept red hot for ten minutes. When they were withdrawn from the fire, the metal was found to have lost its former appearance, and to have acquired the dull white colour of lead or zinc; the insides of the disks were found to present the same whitish appearance, except on the spot where the charcoal was placed, a small part of which still remained unconsumed. As the disks cooled the whitish matter which covered them began to separate, and fly off with some force, in the form of small scales, leaving a clean surface of the proper copper colour. The charcoal was rubbed off, and the surface below it was found smooth and polished; it had acquired a light colour, resembling that of brass; and, near the centre, there was a small spot, which approached to a steel grey. This appearance still continued, after it had been rubbed with fine sand. The above description,” concludes Dr. Bostock, “will probably impress the Society^[247] with the same idea, that, I confess, it gave to myself, that if I had performed this experiment upon a substance, which had been suspected to contain arsenic, and I had not been aware of the appearance that I was to meet with, I should have conceived that I had detected its presence. Upon repeating the process, in precisely a similar manner, except that one grain of arsenic was added to the charcoal, the oxidation of the copper took place as before, and a small part of the charcoal remained unconsumed; but upon rubbing it, the white stain was perfectly visible. However, when these disks were compared with those in which the former experiment had been made, the difference between them seemed more in degree than in kind; so that I should not choose to decide upon the presence of arsenic, as indicated by this test, unless the result were more obvious than we can ever expect to find it, where the quantity of arsenic is so small. It may be proper to observe, that copper, whitened in this manner by arsenic, is very subject to tarnish; in three days I could with difficulty distinguish which of the disks had been employed in these two experiments.”

In connection with the different modes of identifying arsenic by metallization, we may relate a test lately proposed by Mr. A. Thomson, which, as a collateral proof, merits some attention. “Into any solution, in which arsenic may be suspected, stir a moderate quantity of charcoal powder; allow it to settle; then pour off the clear supernatant liquor, or filter the mixture; and when the powder which remains on the filter is dry, sprinkle some of it on a red hot poker; if the solution contain arsenic, the odour of garlic will be rendered sensible. This effect becomes more obvious if a few grains of dry sub-carbonate of potass be added to the dried charcoal powder.”^[248]

If, instead of Black flux, or charcoal, the arsenious acid be heated in a glass tube with quick-lime, a sudden ignition will take place, when one part of the white arsenic will be metallized, and the other farther acidified, so as to produce an arseniate of lime; in this case, therefore, a certain portion of the arsenious acid is robbed of its oxygen to complete the acidification of the rest.

The habitudes of arsenious acid with the nitrates, as first observed by Kunkel, deserve also some attention. If they be heated together, the former will be oxygenated at the expense of the nitric acid, nitrous acid vapour will be disengaged, and an arseniate of potass remain. The forensic chemist may avail himself of these facts, and obtain a very useful test, which may be applied in the following manner.^[249] Take a grain or two of the suspected powder, and mix it with double the quantity of Nitrate of Potass; introduce this mixture in a small glass tube, and apply the flame of a spirit lamp under the powder; when, if it contain arsenic, the nitrate will be decomposed, nitric oxide and nitrous acid be evolved in a gaseous form, and an arseniate of potass remain.

The acid vapour may be easily recognised by its colour and smell, or by placing a piece of moistened litmus paper within the tube. The arseniate may be identified by the brick-red precipitate, produced in its solution, by Nitrate of Silver. So small is the quantity of arsenic required for this latter mode of trial, that Mr. Smithson, in a late paper, observes “that a drop of a solution of arsenious acid in water, which at the height of 54·5 Fah. contains not more than 1/80th of the acid, put to nitrate of potass in a platina spoon, and fused, affords a considerable quantity of arseniate of silver. Hence when no solid particle of oxide of arsenic can be obtained, the presence of it may be established by infusing in water the matters which contain it.”^[250]

a. Fused Nitrate of Silver, or Lunar Caustic. For this test we are indebted to Mr. Hume, who first suggested its application in the Philosophical Magazine for May 1809, (vol. xxxiii). His method of using it is as follows: into a clean Florence flask introduce two or three grains of the suspected substance, in the state of powder, to which add about eight ounces of rain or distilled water, and heat the solution until it begins to boil; then while it boils frequently shake the flask, and add to the hot solution a grain or two of sub-carbonate of potass, agitating the whole to make the mixture uniform. Pour into a wine glass about two table spoonsful of the solution, and touch the surface of the fluid with a stick of lunar caustic. If arsenic be present, a beautiful yellow precipitate will instantly proceed from the point of contact, and settle towards the bottom of the glass as a flocculent and copious precipitate. By this test the 60th part of a grain may be satisfactorily recognised in two ounces of water. The presence of some alkali is essential to the success of the experiment, since arsenious acid is incapable, by the operation of simple affinity, to decompose the nitrate of silver.^[251] The validity of this test has been questioned on several distinct grounds, and which the author has endeavoured to answer in another work^[252]; such, however, is the importance of the question in its judicial consequences, that we shall re-consider it on the present occasion.

Objection 1. The alkaline Phosphates are found to produce precipitates with silver, analogous in colour and appearance to the arsenite of silver. This constituted one of the principal points in the evidence for the defence, on the trial of Donnall for the murder of Mrs. Downing (see Appendix, p. 299), and it must be admitted as a valid objection, if the experiment be performed in the manner just stated; but there are other reagents which will immediately distinguish these bodies, as we shall presently have occasion to state, under the history of the Ammoniuret of silver, as a test for arsenic. The author has also shewn that there is a mode of so modifying the application of the present test, that no error or doubt can arise in the use of it, from the presence of any phosphoric salt. This method consists in conducting the trial on writing paper, instead of in glasses; thus—drop the suspected fluid on a piece of white paper, making with it a broad line; along this line a stick of lunar caustic is to be slowly drawn several times successively, when a streak is produced of a colour resembling that known by the name of Indian Yellow; and this is equally produced by the presence of arsenic, and that of an alkaline phosphate, but the one from the former is rough, curdy, and flocculent, as if effected by a crayon, that from the latter is homogeneous and uniform, resembling a water-colour laid smoothly on with a brush; but a more important and distinctive peculiarity soon succeeds, for, in less than two minutes the phosphoric yellow fades into a sad green, and becomes gradually darker, and ultimately quite black; while, on the other hand, the arsenical yellow remains permanent, or nearly so, for some time, when it becomes brown. In performing this experiment the sun-shine should be avoided, or the transitions of colour will take place too rapidly. It would be also prudent for the inexperienced operator to perform a similar experiment on a fluid known to contain arsenic, and on another with a phosphoric salt, as a standard of comparison.

In this way the nitrate of silver, without the intervention of any other test, is capable of removing every ambiguity, and of furnishing a distinguishing mark between the chemical action of arsenic and that of the phosphates. Mr. Hume^[253] states that he has repeated this modification of his experiment with entire satisfaction; and that, in a late unfortunate case of poisoning, he derived considerable information by its application. One of the great advantages of this test is the very small quantity that is required for examination, and which will therefore never prevent our pursuing the subject through the other channels of investigation.

Objection 2. The muriates produce precipitates with silver, so copious and flocculent, as to overcome every indication which the presence of arsenic would otherwise afford.

From the general use of common salt, the chemist must be prepared to meet with a muriate in almost every examination after arsenic, besides which this latter substance is occasionally adulterated with the muriate of baryta and by sulphate of lime. Dr. Marcet proposes to obviate the difficulties which the presence of a muriate must occasion, by adding to the fluid to be examined dilute nitric acid, and then cautiously applying the nitrate of silver until all precipitation ceases; in this way the muriatic acid will be entirely removed, while the arsenic, if present, will be retained in solution, and may be afterwards rendered evident by the affusion of ammonia, which will instantly produce the yellow precipitate in its characteristic form. It must, however, be confessed, that this mode appears complicated, and, moreover, requires some chemical address for its accomplishment; it should be also known that the yellow precipitate thus produced is not always permanent, for it is soluble in an excess of ammonia. Under these circumstances, it is surely preferable to precipitate at once from the fluid under examination, all the substances which nitrate of silver can affect, and then to expose the mixed and ambiguous precipitate, so obtained, to a low heat, in a glass tube, when the arsenious acid will be separated by sublimation. In this way the presence of muriates and even phosphates, may, in certain cases, be serviceable, especially if the quantity of arsenic be very minute; for, by increasing the bulk of the precipitate, we shall decrease the difficulty of its examination.

Objection 3. Chromate of potass produces with nitrate of silver a yellow precipitate, which, when placed side by side with one produced by arsenious acid, cannot be distinguished by colour or appearance from it. This fact has lately been announced by Dr. Porter, of the University of South Carolina (Silliman’s Journal, iii. 355); but as the presence of Chromate of Potass can never be suspected in any research after arsenic, in cases of forensic interest, it is unnecessary to enter into any details respecting it.

We have stated above, that in consequence of the inability of arsenious acid to decompose nitrate of silver by simple elective attraction, the presence of some alkali becomes indispensable in the examination; and for this purpose Dr. Marcet suggested the superior advantages which would attend the application of ammonia, in all those cases where the arsenic had not been previously combined with a fixed alkali; since the former does not, when added singly, decompose nitrate of silver; a circumstance which, in using the fixed alkalies, is very liable to occasion fallacy. This led Mr. Hume to improve his original plan, by forming at once a compound,^[254] which he calls the Ammoniaco-nitrate of silver, but which may with more propriety be designated, as an ammoniuret of that metal.

b. The Ammoniuret of Silver. This is an improvement of considerable value; for, while it obviates the necessity of ascertaining the exact proportion^[255] of alkali required in each experiment, it possesses the desirable property of not in the least disturbing the solution of phosphate of soda.

c. Sulphate of Copper. This test of arsenic is the one discovered by Scheele; when added to the arsenite of potass a beautiful green precipitate (constituting a pigment known by the name of Scheele’s green) is produced; “so decidedly,” says Dr. Bostock, “does this phenomenon indicate the presence of arsenic, that I thought it desirable to ascertain, as exactly as possible, what were the best proportions in which the ingredients should be employed, and in what way they should be mixed, so as to exhibit the effect in the most obvious manner. After a number of trials, in which the substances were employed in various quantities, and under different circumstances, I am disposed to recommend that the proportions of the arsenic, the potass, and the sulphate of copper, should be to each other as the numbers one, three, and five, respectively; for instance, if one grain of arsenic and three grains of potass, be dissolved in two drachms of water; and, in another equal quantity of water, five grains of sulphate be dissolved, we have two solutions, which are transparent, and nearly colourless; but upon mixing them together, the whole is converted into the most beautiful grass-green, from which a copious precipitate of the same hue slowly subsides, leaving the supernatant fluid nearly without colour. If the same materials are employed, in the same manner, but without the arsenic, a delicate sky-blue is formed, which is so decidedly different from the former colour as not to admit of the possibility of error.” In this experiment then, as well as in that with the nitrate of silver, it is necessary that the arsenious acid should be combined with an alkaline base; and for the same reason, in order to bring the double elective attractions into play; Mr. Hume has accordingly availed himself of the property of ammonia, to form an ammoniuret of copper, which is to be made according to the formula already given for the preparation of the silver test.

d. Ammoniuret of Copper. In using this test care must be taken that it be not too highly concentrated, for in that state it will not produce precipitation.

Notwithstanding the confidence with which Dr. Bostock has supported the pretensions of the Sulphate of Copper, as an infallible test for arsenic, its validity has been lately called in question, and it has been stated that a decoction of onions has the property of imparting to the copper precipitate, produced by a fixed alkali, a green colour and appearance completely analogous to that which is occasioned by the presence of arsenic. This opinion was boldly advanced, and supported, on the trial of Donnall, before alluded to, and of which we have given a very ample report in the Appendix. Since this event an opportunity occurred which enabled the author to examine this alleged fact, by a fair and appropriate series of experiments,^[256] the result of which has satisfactorily proved that the opinion was grounded on an optical fallacy, arising from the blue precipitate assuming a green colour, in consequence of having been viewed through a yellow medium.^[257] The phosphoric salts may also, under similar circumstances, be mistaken for arsenic; for the intense blue colour of the phosphate of copper will, when viewed through a yellow medium, necessarily appear green. Such instances of optical fallacy are by no means uncommon in the history of chemical reagents; thus corrosive sublimate has been said to possess alkaline characters, in consequence of appearing to turn the syrup of violets green, whereas this apparent change is to be solely attributed to the optical combination of the yellow hue of the sublimate with the blue colour of the violet.

Whenever therefore such a source of fallacy can be suspected, the operator would do well to repeat his experiment on white paper, in the manner we have already pointed out, when treating of the silver test; and let it be remembered that the results, when obtained in glasses, should always be examined by day light, and viewed by reflected, and not by transmitted light. Dr. Bostock observes, that a weak solution of the sulphate of copper, without any addition, when held between the eye and the window, frequently presents a greenish tinge. It should be also known that the usual reaction of the ammoniuret of copper, upon a diluted solution of arsenic, is prevented by the presence of tannin; strong tea may therefore render the test inefficient.

e. Sulphuretted hydrogen. This is a very delicate test for arsenic, producing with its solution a beautiful golden coloured liquor, which, after a short time, lets fall a precipitate, and which will take place sooner if a small quantity of acetic acid be added. By this re-agent so small a quantity as 1/100000 may be detected in solution. The test, however, is not, says Dr. Bostock, sufficiently discriminative to be depended upon alone; since tartarized antimony and some other bodies, will produce phenomena that may be mistaken for the effects of arsenic. It has, however, the merit of not being affected by tannin, and may therefore be conveniently employed for precipitating arsenious acid, when dissolved in tea.

f. Lime water produces with the solution of arsenic a beautiful white precipitate of arsenite of lime, which easily dissolves in an excess of arsenious acid.

The precipitates occasioned by the foregoing reagents, should be carefully collected, and treated with black flux, in a glass tube, for the purpose of obtaining the metallic sublimate, as above described.

We cannot quit this part of our subject without directing the reader’s attention to the chemical evidence given by Dr. Addington, on the trial of Mary Blandy (see Appendix, p. 241) to prove that arsenic was contained in a powder with which she was supposed to have poisoned her father. To those in the least acquainted with the habitudes of arsenious acid, it must be evident, that no one of the appearances described by Dr. Addington indicates the presence of arsenic;^[258] and his evidence is only to be reconciled upon the supposition that, instead of the arsenic itself, he, in this case, detected the foreign substances with which it had been adulterated; thus it has been before stated that white arsenic, as sold by the druggists, is often adulterated with sulphate of lime; and the decomposition of this substance by the sub-carbonate of ammonia (“Spirit of sal-ammoniac”) or by the sub-carbonate of potass (“Lixivium of tartar”) would occasion the precipitation of a white substance, as stated in the evidence; it is however difficult to account for the “considerable precipitation of a lightish coloured substance” by muriatic acid (spirit of salt) by the presence of any impurity likely to be contained in the arsenic, or in the water employed for its solution. If any lime were present, it would probably give “white glittering crystals” of sulphate of lime, by the addition of sulphuric acid (spirits of vitriol). The only plausible evidence of the presence of arsenic in the suspected powder is “the alliaceous smell and white flowers” which Dr. Addington describes as occurring when it was thrown on red hot iron; it must however be confessed, that from the fallacy of the other experiments, it is even impossible to place any confidence in those last mentioned.

Arsenic does not blacken a knife by which it is cut, as stated on the trial of Eliza Fenning; nor does it, when mixed with dough, prevent its rising.^[259]

We have now concluded our history of the different tests which have been proposed for the detection of arsenic. Much has been said and written upon the relative degree of confidence to which they are respectively entitled, and it has been asserted on several occasions, that nothing short of the reproduction of the metal ought to be received by the tribunals of justice, as an unequivocal proof of the presence of arsenious acid. (See Dr. Neale’s Evidence on the trial of Donnall. Appendix, p. 297.) In taking an impartial review of all the evidence which the investigation of this subject can furnish, it must appear to the most fastidious, that the Silver and Copper tests, above described, are capable, under proper management and precaution, of furnishing striking and infallible indications; and that in most cases they will be equally conclusive, and in some even more satisfactory in their results, than the metallic reproduction upon which so much stress has been laid; and for this obvious reason, that unless the quantity of metal be considerable, its metallic splendour and appearance is often very ambiguous and questionable. The author is personally acquainted with a case, where the medical person, by no means deficient in chemical address, actually ascribed the presence of arsenic to that which was no other than a film of finely divided charcoal: in this state of doubt the last resource was to ascertain whether it yielded, or not, upon being volatilized, an alliaceous odour. Surely an unprejudiced judge would prefer the evidence of sight, as furnished by the tests, to that of smell, as afforded in the experiment to which we allude; especially after the various fallacies, which we have shewn in the course of the present enquiry, to have occurred with regard to this latter sense. But the question at issue may be easily disposed of to the satisfaction of all parties; for let it be remembered, that the application of chemical reagents on solutions suspected to contain arsenic, so far from throwing any obstacle in the way of the metallic reproduction of that substance, are the very steps which should be adopted as preparatory to the “experimentum crucis.” It is only necessary to collect the precipitates, and to decompose them in the manner already described; and this confirmation of our results should never be neglected, for it is the bounden duty of the forensic chemist, who is called upon to decide so important a question as the presence of a corrosive poison, to prosecute by the fullest enquiry every point which admits of the least doubt; he should also remember that in a criminal case, where the life of a human being depends upon his testimony, he has not only to satisfy his own conscience, but that he is bound, as far as he is able, to convince the public mind of the accuracy and truth of his researches.

The detection of the presence of arsenic, amidst a complicated mass of alimentary matter, has long been a problem of interest and difficulty. In the directions which have been already offered for the discovery of arsenic in solution, we have in some measure anticipated several of the resources, of which we are now to avail ourselves. It has been seen how greatly coloured fluids are capable of obscuring, and changing, and even altogether preventing, the arsenical indications. M. Orfila, with an assiduity and accuracy which so eminently characterise all his toxicological labours, has accordingly investigated the peculiar appearances assumed by the arsenical precipitates in different media, such as bile, tea, coffee, wine, broth, jelly, &c. Since the publication of the great work^[260] in which these phenomena are recorded, its author has proposed a new method^[261] of removing its difficulties and embarrassments, occasioned by the colouring matter of the above media; which consists in a previous application of Chlorine, so as to change the colour to a shade, that will not offer any optical impediment to the characteristic indications of the tests in question. We are ready to admit that such a mode of proceeding may, on certain occasions, assist the accomplished chemist in his analysis; but in the hands of a person less accustomed to chemical manipulation, we hesitate not to declare that it is subject to fatal fallacies; whereas, by collecting the precipitate, and submitting it to the process of sublimation we shall at once obtain the arsenious acid in a pure form, and be enabled to test it, in distilled water without the chance of error. Why then should we attempt to pursue our game through the windings of a labyrinth, when a direct road lies before us by which we may drive it into the open plain?

We accordingly recommend the juridical chemist, who suspects the presence of arsenious acid in broth, coffee, or any coloured liquid, to add a solution of ammoniuret of silver, and thus to precipitate indiscriminately all the bodies which it may be capable of so affecting. The precipitate may then be collected, and submitted to heat in a glass tube, as before directed.

But the Arsenious acid may perchance be so mixed with various foreign matter as to render its separation by filtration difficult; in such a case, after having boiled it in distilled water, in order to procure all the soluble matter from it, the residual mass may be evaporated to dryness, care being taken that the heat applied for such a purpose never exceeds 250° Fah. or we shall lose the arsenic, should any be present, by volatilization. The residue thus obtained may then be submitted to a higher temperature in a subliming vessel, in order to procure the arsenious acid in its pure state. This process applies particularly to the examination of the matter vomited, or the feculent evacuations passed, by the patient. Should the arsenious acid have, in the first instance, been dissolved in oil, Dr. Ure proposes to boil the solution in distilled water, and to separate the oil afterwards by the capillary action of wick threads. If the arsenious acid be mixed with resinous bodies, Oil of Turpentine may be employed as their solvent, which will leave the arsenic untouched. Dr. Black directed the application of alcohol for this purpose, but this is obviously improper, since arsenious acid is soluble in that fluid.

If the physician be called upon to investigate the contents of the alimentary canal after death, and the arsenious acid cannot be discovered amongst the suspected matter, the stomach itself must be cut into small pieces, and in compliance with the directions of Orfila, boiled in ten or twelve times their weight of distilled water, which should be renewed as fast as a portion of it flies off in vapour; this liquor should be cooled and decanted, in order to put a few drops of it into the solutions of the different re-agents which we have before described. If the precipitates should indicate the presence of arsenic, we may proceed according to the directions we have already laid down; if, on the other hand, the fluid offers no indication of poison, the mass exhausted by water should be treated, according to the process suggested by Rose, by boiling it for some time in a solution of potass, by which means the stomach will be partly decomposed and dissolved, and the arsenious acid, with which it might have been combined, saturated by the alkali. In this state the liquor is to be filtered, again boiled, and nitric acid added, little by little, until it passes from a dark to a clear yellow colour. The object of the acid in this stage of the process being to decompose and destroy the animal matter. The excess of acid should be saturated with potass, when an Arsenite of Potass will be formed, if there really existed any arsenious acid in the stomach. This M. Orfila recommends us to precipitate by the Hydro-sulphuret of Ammonia, and a few drops of nitric acid; (Rose prefers lime water for the same purpose); a yellow sulphuret of Arsenic will be the result, from which the whole of the metal may be obtained, by drying it upon a filter, mixing it with an equal bulk of potass, and melting it in a small glass tube.

This complicated mode of proceeding will rarely be found necessary; but it should not be neglected, where the presence of arsenic cannot be otherwise detected in the alimentary canal of those who are suspected to have died from its ingestion, especially in the examination of a body where, from the length of time it may have been under ground, there is reason to suppose that the acid exists in a state of intimate combination with the animal matter. And we may take this opportunity to observe, that advanced putrefaction, however disagreeable it may render such researches, will not, in the case of arsenic, defeat their success; let the forensic physician, then, remember, that the length of time which may have elapsed since the death of the body, ought never to be urged as a plea for not having proceeded in its dissection. The task may be personally disagreeable, but it will be less painful than the reflections which must attend a breach of duty; upon such an occasion we would address the anatomist in the quaint but expressive words of Teichmeyer^[262], “PrÆstat enim manus quam conscientiam cruentare et contaminare.”

Arsenic Acid, and its Salts.

It has been stated, that the Metal Arsenic is susceptible of two degrees of oxidizement, the result of its first degree being Arsenious acid, and that of its second Arsenic acid. This latter compound, of which we are now to treat, may be obtained by the repeated distillation of white arsenic with nitric acid. In a solid state it is white, not crystallizable; of a sour, and at the same time, metallic taste; its specific gravity is 3·391; when exposed to the action of heat in a close vessel, it does not become volatile, but melts and vitrifies; thrown on burning coals, it swells, parts with its water, and becomes opaque; if the process of deoxidation be continued, it will, at length, rise in vapours, like those of arsenious acid, and which, like them, will yield an alliaceous odour, or not, according to the circumstances already explained. The Arsenic acid dissolves very readily in water, and is even indeed deliquescent. With alkalies, earths, and oxides, it constitutes a class of salts, called “Arseniates,” all of which, as well as the pure acid, are extremely active poisons; fortunately, however, they are not much employed^[263] in this country, and are not likely to become the instruments of crime. These salts, like those of the arsenious acid, are obedient to the different re-agents which were enumerated under the consideration of this latter substance, but with different results; thus the silver test, instead of producing the yellow indication, occasions an equally characteristic precipitate of a red, or brick colour. The ammoniuret, and acetate of copper, furnish a bluish-white precipitate. The arsenic acid, in a solid form, or the arseniate, mixed with black flux, will, like white arsenic, furnish a metallic sublimate, when heated in a glass tube.

The Sulphurets of Arsenic.

There are two Sulphurets of Arsenic: the yellow variety known in commerce under the name of Orpiment, and the red sulphuret, termed Realgar. The bodies, as they occur native, do not appear to be endowed with the virulent powers which distinguish the other compounds of arsenic. M. Renault^[264] gave as much as two drachms of the native orpiment to dogs of different sizes, from which they experienced no inconvenience. Hoffman^[265] also offers his testimony of the inertness of this substance. The same observations apply to the Realgar. It is not a little singular that while these native sulphurets of arsenic should be so harmless, those which are produced by artificial fusions, are extremely virulent in very small doses. M. Renault supposed that this remarkable difference of effect was owing to the arsenic being oxidized in the latter compound, and in its metallic state in the former. This explanation, however, is not considered as satisfactory by M. Orfila, who states that it does not embrace all the varieties of the case, for that the sulphuret, which is artificially obtained by pouring the arsenious acid into a solution of sulphuretted hydrogen, is as inert as the native compounds; besides which, chemical analysis has proved that there is no oxygen in any of these sulphurets, and that they only differ from one another, by a greater or less proportion of their two ingredients. This apparent anomaly induced M. Orfila to institute a series of experiments for its investigation, but the results which he has obtained are too unsatisfactory to enable him to decide the question.

The presence of an Arsenical Sulphuret is to be sought for by calcination with caustic potass, in a small glass tube. The sulphuret is decomposed in a few seconds, yielding its sulphur to the potass, while its metallic element is volatilized with the usual phenomena.

Mercury.

Mercury, or Quicksilver^[266], was known in the earliest ages. Its external characters are too familiar to require any particular description in this place. Its specific gravity is 13·568.^[267] In its metallic state it exerts no action on the living system, except that which may depend upon its mechanical properties, although a different opinion has been entertained, (see Pharmacologia, art. Hydrargyrum.)

Several of the combinations of this metal are, however, highly destructive in small doses, and are consequently objects of forensic interest.

This metallic salt is by far the most active of all the mercurial preparations. According to the latest views of Chemistry it is a compound of two proportionals of chlorine, and one proportional of metallic mercury, and is therefore a bi-chloride of Mercury. It generally occurs in the form of a crystalline mass, made up of very small prismatic crystals, which undergo a slight alteration by exposure to air, becoming opaque and pulverulent. Its taste is extremely acrid, with a metallic astringency, occasioning a sensation of obstruction in the throat which continues for some time. Its specific gravity is 5·1398^[268]. When pulverised and thrown upon burning coals, it is immediately volatilized, giving out a thick white smoke, of a very pungent smell, not at all resembling garlic, but which irritates the mucous membranes extremely, and is highly dangerous to those who breathe it. It is soluble in eleven parts of cold, and in three of boiling water; and this solubility may be farther increased by the addition of a few drops of rectified spirit, or of muriatic acid. When swallowed in small quantities it acts as a most virulent poison.^[269]

Symptoms of Poisoning by Corrosive Sublimate.

The effects, as well as the modus operandi, of this salt, will vary with the quantity swallowed. We shall, therefore, first consider the acute symptoms which supervene a dose sufficiently powerful to destroy life in a few hours; and afterwards those which may arise from its long continued use in small quantities, and at different intervals.

1. Symptoms which follow a large dose. A most painful burning and sense of constriction is experienced in the fauces; dryness of the mouth and lips; excruciating pain in the stomach and bowels, increased by the slightest pressure, and generally attended with considerable distention; excessive vomiting and purging of frothy mucus; the countenance is frequently red and swollen, and the eyes exhibit a sparkling appearance, accompanied by contraction of the pupils. The pulse is in general quick, small, and hard; suppression of urine takes place, and cold sweats; anxiety; universal pains; convulsions, and death. If the patient survives long enough, a violent ptyalism, and sloughing of the mouth and gums may take place.

2. Symptoms which are produced by the repetition of small doses. In this case the mercurial salt acts as an “Accumulative Poison.” (See page 148). The most striking of the symptoms are those arising from its specific action upon the salivary glands, in consequence of which an increased flow of saliva takes place, the gums become tender and sore, the breath intolerably offensive, and if the use of the salt be not discontinued, the teeth loosen, and even fall out, and their loss is sometimes followed by that of the bones of the palate, or maxillÆ; at the same time other evils, although perhaps less apparent, soon arise; the strength and muscular powers of the body begin to fail; emaciation proceeds rapidly; cardialgia, dyspepsia, diarrhÆa, and a train of morbid symptoms succeed; violent pains are experienced in the muscles, tendons, or joints; tremors of the limbs, and even paralysis may result; and in some cases, pulmonary consumption terminates the existence of the unhappy sufferer. It has been asserted that Corrosive Sublimate, when taken for a long time in small quantities, will sometimes occasion all the symptoms of debility above enumerated, together with hectic fever, without producing salivation. This is a truth which the author’s personal experience will enable him to confirm. The Countess of Soissons, mother of the celebrated Prince Eugene, was accused, at the latter end of the seventeenth century, of having destroyed her husband by these means. A question of considerable importance has arisen, with regard to the specific effects of mercury, which demands some notice in this place. Whether salivation, after having entirely subsided, can ever return without a fresh exhibition of Mercury? Two instances are related by Dr. Mead of the return of salivation, after an interval of several months, when not a particle of mercury had been administered, in any form, during that period.^[270] Dr. Male, in his work on Juridical Medicine,^[271] relates an analogous case which occurred in his own practice: “In March, 1815,” says he, “I gave a small quantity of triturated mercury to a respectable woman in this town, who had been long ill; she became suddenly and unexpectedly salivated. She soon recovered, and enjoyed better health than she had done for a considerable time. In October, without (as she informed me) having taken any medicine whatever, the salivation returned with extreme violence, her mouth sloughed and mortified; and in a few weeks she died.” Dr. Hamilton, the Professor of Midwifery in Edinburgh, relates in his lectures the case of a married lady, who had been under the necessity of going through a course of mercury, under the care of the late Mr. Bennet, who, from motives of delicacy did not enquire very minutely into the particular circumstances; but, according to the rule of the day, gave his patient a sore mouth. Four months afterwards she miscarried, and salivation again came on. It was removed for a week, at the end of which it returned, and harrassed her for about twelve months.^[272] The author, in his Pharmacologia,^[273] has cited a case from Hufeland’s Journal, (vol. ix) wherein mercurial influence, after its complete subsidence, had been renewed by doses of opium. In the trial of Miss Butterfield, at the Croydon assizes, for poisoning Mr. Scawen, in the year 1775, the merit of the case entirely hinged upon this question. See vol. 1, p. 303.

Physiological action of Corrosive Sublimate.

When this salt is introduced into the stomach in a large dose, it immediately exerts a corrosive action on that organ, in consequence of which the heart and brain become sympathetically affected, and death results from the suspension of their functions. For this view of the modus operandi of this mercurial salt we are indebted to Mr. Brodie,^[274] whence it would appear that its physiological action is very different from that of arsenious acid; the former acting as a simple escharotic, on the coats of the alimentary canal, the latter requiring to be absorbed, before it can display its energies. These observations, however, apply only to those cases in which the quantity of poison has been so considerable as to destroy life in a few hours; where the dose has been small, and the symptoms have arisen from its frequent repetition, the salt produces its effects by a different mode of operation. In this latter case it is absorbed, and carried into the current of the blood, so as to be distributed to every part of the living system; and it has been asserted that, after the long continued and improper use of mercury, it has been discovered in different parts of the body, and even in the brain, in the form of globules. In this way then deleterious effects may arise from the external application of corrosive sublimate, and numerous instances are recorded where such consequences have followed the injudicious use of lotions and plasters, into which it had entered as an ingredient.^[275] In the Medical Repository, for December, 1821, Mr. Sutleffe has communicated the case of a girl of five years of age, who became salivated, and died, in consequence of an application made to the head for tinea capitis, consisting of pomatum rubbed up with a few grains of corrosive sublimate.

Antidotes to Corrosive Sublimate.

After the view which we have taken of the operation of this salt in large doses, it necessarily follows that copious dilution is the very first object which we have to accomplish, and then the ejection of the fluid by vomiting. Sydenham relates an interesting case of poisoning by this substance, which was successfully treated by copious draughts of water, and repeated vomiting.^[276] But it becomes a question of great practical importance to enquire, whether there may not exist some counterpoison or antidote which, by decomposing the salt, will at once disarm it of its virulence? This question has been investigated in a very masterly style by Orfila, who has clearly proved by experiment, that neither the alkaline salts and earths, the sulphurets of potass and of lime, nor the martial alkaline tinctures, as proposed by Navier,^[277] deserve the least confidence; for although the salt may by some of these bodies be decomposed, yet the resulting oxide will prove as virulent as the original compound; equally inefficient are the other substances which have been proposed as counter-poisons, such as sulphuretted hydrogen, solutions of sugar,^[278] the infusions of Peruvian bark,^[279] and metallic mercury.^[280]

M. Orfila having observed the facility with which albumen decomposes corrosive sublimate, and gives rise to a triple compound of albumen, muriatic acid, and protoxide of mercury, induced him to ascertain by experiments whether the white of eggs might not prove an antidote to that poison; the result of his inquiry has shewn that this is the case; and that by mixing such albuminous matter, in large quantities, with the diluents given to provoke vomiting, the happiest effects may be anticipated. Many examples are recorded of the success of this practice. In the Transactions of the King and Queen’s College of Physicians in Ireland, an interesting case of this kind is related by Dr. Lendrick; it is, however, but justice to state, that there are instances also of the failure of this antidote. In the 41st volume of the London Medical and Physical Journal, p. 204, the reader will find the case of a girl who was poisoned by a drachm of sublimate, and who, notwithstanding the copious administration of albumen, died in ninety hours afterwards.

It has lately been discovered that vegetable gluten, as existing in wheat flour, is capable of producing upon corrosive sublimate the same chemical decomposition, as that which we have stated to arise from the action of albumen; whence the administration of wheat flour and water has been suggested as a ready antidote. On the trial of Michael Whiting, for administering poison (corrosive sublimate) to his brothers-in-law, George and Joseph Langman, the housekeeper, Catharine Carter, stated in evidence, that the flour, (which was subsequently proved to contain corrosive sublimate) could scarcely be made into dumplings with milk^[281]; and another witness, Mrs. Hopkins, a neighbour who took charge of the dumpling that had not been boiled, described it as “a comical sort of paste; like glazier’s putty more than paste, though not greasy.” In order to ascertain the correctness of this statement, we mixed powdered sublimate with wheat flour, and proceeded to make it into dough with milk; when the same difficulty as that stated by the above witnesses, embarrassed the process, and satisfied us of the truth of their testimony. The phenomenon would appear to depend upon the mutual chemical changes which arise in the gluten and mercurial salt.

Organic Lesions discovered on Dissection.

The oesophagus and stomach will be found inflamed, and sometimes eroded, as in poisoning by arsenic. Salin has asserted, that this salt never produces perforation of the intestinal tube; this, however, is not the fact; and we know not of any exclusive appearances, by which the organic lesions inflicted by this poison can be distinguished, unless indeed it be the black appearance of the stomach, as if it had been burnt, which occasionally presents itself.

As the chemist, devoted to forensic enquiry, will be required to identify this substance under very different states of mixture and combination, we shall proceed to enumerate the various obstacles that may possibly oppose his researches; and, at the same time, to suggest the expedients by which they may be successfully evaded. Unlike arsenious acid, corrosive sublimate is so readily decomposed by various alimentary substances, that, when we attempt to demonstrate its presence in such mixtures, we shall be more frequently compelled to rest our proof upon the products of the analysis, than upon the actual reproduction of the salt.

We shall proceed to consider the best modes of establishing the presence of this salt, in the different forms in which it may occur, viz. 1, In the solid form; 2, Dissolved in water or spirit; 3, In various coloured liquids; 4, In a state of mixture with various solids; 5, Combined with solid or liquid aliments, by which it undergoes decomposition; 6, In a state of combination with the textures of the alimentary canal.

1. The sublimate is in its solid form. The external characters by which this salt is distinguished will go far to establish its identity; but the fact should always receive the support of a chemical proof; and as this is to be derived from the phenomena afforded by its solutions through the intervention of various tests, it will meet with full consideration in the following section, viz.

2. The salt is in the state of solution, in water, or spirit. Let us then suppose that we have a solution of some body in distilled water, which we suspect to be corrosive sublimate, by what means are we able to identify it?

(a) By its metallization, through the agency of galvanism. We are indebted to Mr. Sylvester for first suggesting the mode by which galvanic electricity might be applied for the detection of minute quantities of corrosive sublimate in solution. His method is as follows. A piece of zinc or iron wire, about three inches in length, is to be twice bent at right angles, so as to resemble the greek letter p, the two legs of this figure should be distant about the diameter of a common wedding ring from each other, and the two ends of the bent wire must afterwards be tied to a ring of this description. Let a plate of glass, not less than three inches square, be laid as nearly horizontal as possible, and on one side drop some sulphuric acid, diluted with about six times its weight of water, till it spreads to the size of a halfpenny. At a little distance from this, towards the other side, next drop some of the solution supposed to contain corrosive sublimate, till the edges of the two liquids become joined; and let the wire and ring, prepared as above, be laid in such a way, that the wire may touch the acid, while the gold ring is in contact with the suspected liquid. If the minutest quantity of corrosive sublimate be present, the ring, in a few minutes, will be covered with metallic mercury on the part which touched the fluid.

The above experiment may be beautifully simplified in the following manner^[282]. Drop a small quantity of a solution, supposed to contain the salt in question, on a piece of gold, and bring into contact a key, or some piece of iron, so as to form a galvanic circuit; when, if sublimate be present, the gold will immediately be whitened.

A solution of nitrate of silver will, under similar treatment, occasion on gold a white precipitate; but as no amalgamation takes place, it is readily wiped off, and cannot therefore occasion any fallacy.

(b) By precipitating metallic mercury from its solution, by the contact of a single metal. It should be generally known that, by virtue of superior affinity, certain metals will decompose the solution of corrosive sublimate, with different phenomena; in those cases where the precipitating metal is capable of forming a direct union with mercury, we shall find the precipitates to consist of an amalgam of the metal employed; where no such combination takes place, the mercury may be frequently seen standing on the surface as a metallic dew. This is particularly striking when iron or steel has been employed. In the evidence given on the trial of Mary Bateman^[283], better known by the name of the “Yorkshire Witch,” Mr. Thomas Chorley, surgeon at Leeds, stated that he had received from his assistant, Mr. Hammerton, a jar which he had carefully preserved in his possession, and of the contents of which he gave the following account. “Upon tasting a portion, it was very acrid, styptic, and permanent upon the tongue; I then took a small quantity of it upon a clean knife, and rubbed it with my finger; a change of colour immediately appeared; further rubbing produced numerous globules of quicksilver, and the knife was, at the same time, blackened by it; this change of colour led me to suspect that it must be a mercurial composition, and having made a solution of it, and subjected it to a series of tests and experiments, it is my opinion, that the mixture in the pot did contain honey, and corrosive sublimate of mercury. In order, however, more fully to satisfy myself upon this point, a mixture was made of these ingredients, when it was found to yield the same results.” In the above experiment, the steel knife decomposed the sublimate, forming a chloride of iron, while the mercury, thus disengaged in its metallic form, being unable to amalgamate with the iron, appeared in globules^[284] upon its surface. At the same time the knife became blackened owing to the precipitation of carbonaceous matter from the steel.

(c) Carbonate of Potass. A saturated solution of this salt, added to that of corrosive sublimate, will produce a deep brick coloured sediment, which is stated to consist of per-carbonate of mercury^[285]; while a muriate of potass will be found to remain in solution. The sub-carbonate of potass will occasion a somewhat different precipitate, of a clear brick colour, and consisting of a mixture of the carbonate, and oxide of the metal.^[286]

(d) Ammonia. A solution of the volatile alkali produces a white precipitate, which is an insoluble triple salt, composed of muriatic acid, ammonia, and oxide of mercury; being heated it grows yellow; it passes afterwards to red, and according to Orfila gives out ammoniacal gas, nitrogen, calomel, and metallic mercury. In this operation the oxide of mercury is supposed to be deoxidized by the hydrogen which results from a portion of the decomposed ammonia.

(e) Lime water. This reagent may be said to decompose corrosive sublimate more perfectly than any alkaline body; occasioning a precipitate of a deep yellow colour, which will be found to be a peroxide of mercury; unless indeed the quantity of lime water be very small, when it will be a sub-muriate of the peroxide.

(f) Nitrate of Tin. According to Dr. Bostock^[287] this test is capable of detecting the three-millionth part of a grain in solution. A single drop will produce an immediate and copious dark-brown precipitation.

All the above precipitates, if rubbed on a bright plate of copper, will render its surface silvery white, in consequence of the amalgamation which takes place.

Brugnatelli has lately proposed a method of distinguishing corrosive sublimate from arsenic, which we have repeated to our satisfaction; but the experiment requires some nicety of manipulation to secure its success. Take a quantity of fresh wheat starch, mix with water, and add a sufficient quantity of iodine to give the liquid a blue colour; if either of the above poisons be now introduced into it, the colour will be destroyed, and assume a reddish tint; but if the change has been effected by the latter substance, a few drops of sulphuric acid will restore the blue colour; whereas if it has been produced by the former, it is not recoverable by such means.^[288]

3. It is dissolved in various coloured liquids. Under this subdivision we have to consider the corrosive sublimate as existing in a state of solution, in liquids, whose colour will be liable to obscure the characteristic indications which the several reagents would otherwise occasion. It has been proposed to obviate such impediments by the previous addition of chlorine, which will discharge the colour in question. Orfila recommends such a process, where the salt has been dissolved in wine. The same objections which we urged against this mode of proceeding, under the consideration of arsenic, appear to us to apply to corrosive sublimate.

It will be preferable on these occasions to precipitate the salt by an appropriate reagent, and then to assay the precipitate for metallic mercury; or to evaporate the solution, and to submit the matter so obtained to the process of sublimation, when the sublimate may be dissolved in distilled water, and examined by the tests above described. This circuitous process may, however, in many cases be rendered unnecessary, by dropping the solution on the surface of white paper, and in such a situation proceeding to its examination by tests; when the colour of the precipitate will rarely be exposed to any optical fallacy. The Galvanic process of metallic reduction will also furnish a satisfactory solution of the problem.

4. It is mixed, or combined, with some medicinal body in a solid form. As persons have been poisoned by empirical remedies, and other medicines containing sublimate, accidentally or by design, it is necessary to point out the readiest mode by which the investigation may be pursued. If it should form part of a plaster, it will be adviseable to cut it up in small pieces, and boil them for a quarter of an hour in distilled water; this fluid, after standing for some time, should be filtered, and examined as we have before directed. It is evident that, if the sublimate is neither decomposed, nor strongly retained by the materials which compose the plaster, it ought to be found in the above solution; if, however, no such result can be obtained, the solid portion should be dried in a capsule, and mixed with potass; and in this state submitted, in the usual manner, to the process of sublimation, when the appearance of metallic globules will announce the existence of the salt in question, or, at least, of the presence of some mercurial preparation.

5. It is united with alimentary substances which have effected its decomposition. It has been frequently stated during the course of the present inquiry, that corrosive sublimate is easily susceptible of decomposition, and that various alimentary substances, of animal as well as vegetable origin, have the power of converting it into calomel.^[289] This important fact was first noticed by Chaussier^[290] and has been more fully investigated and confirmed by Orfila.^[291] Where the quantity of mercurial salt has been considerable, we may generally obtain, on washing the alimentary matter, a sufficient portion for experiment; but where the dose has been small, or where it has been ejected by frequent vomiting, the whole residue may be decomposed; in which case we must seek to establish the fact of poisoning, through the detection of metallic mercury, by the processes of calcination and sublimation.

6. It is decomposed, and a part exists in intimate combination with the membranes of the alimentary canal. If all the preceding experiments have failed in detecting the presence of corrosive sublimate, it becomes our duty to examine the textures with which it may be supposed to have come in contact; the coats of the canal should be cut into pieces, and calcined with potass, when, if they have been acted upon by sublimate, they will yield metallic mercury by sublimation. “The alimentary canal,” says M. Orfila, “acts upon the sublimate like all other animal substances; muriatic acid is disengaged, and muriate of mercury ad minimum (calomel) is formed, which combines with the substance of the viscus.

It may be objected,” continues this distinguished experimentalist, “that this chemical action does not take place in the living animal; that our texture, while endued with the vital principle, is not subservient to the same laws as inorganic substances: I am not ignorant of the extent to which this objection is well-founded; but admitting the justice of it, the conclusion is not less true, that if the stomach contains corrosive sublimate at the moment of death, this body will, from that moment, act on the texture of the viscus itself. If the stomach contain a large quantity of aliment, the effects of such an action may be scarcely perceptible; but on the contrary, they will be easily applicable, should the viscus be empty, and especially if the examination of the body takes place several days after death.”^[292]

In conducting experiments upon this, and indeed all other mineral poisons, the chemist must be prepared to meet with anomalies depending upon the impurities or adulterations of the substance under examination.

Red Oxide of Mercury. Precipitate per se.

We are not aware of any instance of death having, from accident or design, taken place in consequence of the administration of this substance; indeed its red colour, insolubility in water, and comparative rarity, will protect mankind sufficiently against mistake, and at the same time render its secret administration extremely difficult. It is, moreover, mild in its effects, unless in large doses, or, under particular circumstances of constitution. It may be identified by its form, which is that of minute crystalline scales, of a deep red colour, and by exposing it to heat in a glass tube, by which it undergoes decomposition, giving out metallic mercury, adhering to the sides of the tube, and oxygen gas, which is disengaged.

Red Precipitate, or Nitric Oxide of Mercury.

This is, strictly speaking, a sub-nitrate of mercury, and is much more poisonous than the preceding substance. Plouquet^[293] relates the case of a man, who swallowed by accident some red precipitate, when he immediately experienced violent colics, copious vomitings, a trembling of his limbs, and cold sweats. Its external characters will at once enable the chemist to identify it.

Other Preparations of Mercury.

The various saline compounds of this metal, as the acetate, sulphate, and nitrate, are all highly poisonous, but they do not appear to us to merit a separate consideration; and more especially as we have already explained the various processes by which every variety of preparation may be identified. We may just remark that the sulphuret, better known by the name of cinnabar, or vermilion, has been known to occasion deleterious effects. Dr. Gordon Smith^[294] states, upon the authority of Mr. Accum,^[295] that “Vermilion has been detected as a poisonous ingredient in cheese:” this may be very true, but he should have stated at the same time, that the deleterious effects produced by it, did not arise from the mercurial sulphuret, but from the red lead with which it happened to be adulterated; and it is necessary to acquaint the forensic chemist, that such a fraud^[296] is by no means uncommon; it may be very easily detected by burning a small portion of the suspected sample on a piece of bread in the candle, when metallic globules will announce the presence of lead; for the oxide of mercury, although revived by the process, will at the same time be volatilized. The bread by combustion affords the carbon by which the metallic reduction is effected.

The presence of very minute quantities of vermilion may, according to Mr. Smithson, be detected by the following simple experiment. Boil a portion with sulphuric acid in a platina spoon, and lay the sulphate thus produced in a drop of muriatic acid, on a piece of gold, and then bring a piece of metallic tin in contact with both, when the white mercurial stain will be produced.

Antimony.

Although the ancients were entirely ignorant of this metal, they were well acquainted with several of its combinations,^[297] Basil Valentine, a German Benedictine Monk, was the first who described the process for obtaining it from its ore; to this work, originally written in high Dutch, and known by the title of the “Currus Triumphalis Antimonii,” which was published towards the end of the 15th century, we are indebted for almost all our knowledge respecting this metal.

Antimony is of a greyish white colour, having considerable brilliancy; its texture is laminated, and exhibits plates crossing each other in every direction; its specific gravity is 6·7021; when rubbed upon the fingers it communicates to them a peculiar taste and smell; it is very brittle, and fuses at the temperature of 809°, but does not appear to be volatile; when fused, with the access of air, it emits white fumes, consisting of an oxide of the metal, which formerly was called Argentine flowers of Antimony. When the metal is raised to a white heat, and suddenly agitated, it enters into a state of combustion, and is converted into the same white coloured oxide.

According to Thenard,^[298] antimony is susceptible of no less than six different degrees of oxidation; Proust, however, has shewn that they may all be reduced to two, viz. protoxide and peroxide. The former of which alone exerts any sensible activity upon the human body; but this constitutes the basis of several preparations, which although in common use for medical purposes, are so extremely poisonous in larger doses, as to render them objects of interest to the forensic physician.

This saline body appears in the state of white crystals, whose primitive figure is the regular tetrahedron, although it assumes a variety of secondary forms. Its chemical composition is still involved in some obscurity; it is stated, in the different dispensatories, to be a triple salt, consisting of tartaric acid, oxide of antimony, and potass, and that it ought therefore, according to the principles of the reformed nomenclature, to be termed a Tartrate of Antimony and Potass. The truth of these views, however, we have already^[300] ventured to question; Gay Lussac has stated that in the various metalline compounds of which Super-tartrate of Potass is an ingredient, this latter substance acts the part of a simple acid; an opinion which receives considerable support from the great solvent property of cream of tartar, and from the striking fact that it is even capable of dissolving various oxides which are insoluble in tartaric acid, of which the protoxide of antimony is an example. In such a state of doubt, a better name could not be found than that of tartarized antimony.

The salt, according to Dr. Duncan, is soluble in three times its weight of distilled water at 212° Fah. and in fifteen, at 60°.

When it is heated red hot in an earthen crucible, it blackens, and undergoes decomposition like a vegetable body, leaving a residuum of metallic antimony, and slightly carbonated potass.

A question has arisen whether this salt can be considered as a poison, capable of occasioning death? In general where a large dose has been administered, it is all rejected by the vomiting which it excites; we accordingly find in the works of Morgagni and other pathologists, the history of various cases in proof of the innocence of this salt. Hoffman, however, relates the case of a woman who experienced very severe symptoms shortly after having taken tartar emetic, and that she ultimately died,^[301] and there are other similar instances recorded in the works of FoderÉ and Orfila. It also deserves notice, that tartarized antimony is very liable to produce deleterious effects, where, from the insensibility of the nervous system, the operation of vomiting cannot be excited, as in apoplexy, drunkenness, and in that state of coma, which follows the ingestion of narcotic vegetables. M. Cloquet communicated to Orfila a case highly illustrative of this fact, in which a person, labouring under apoplexy, received into his stomach more than forty grains of tartar emetic, without exciting either nausea or vomiting. On opening the body, independent of the morbid state of the brain, which must be regarded as the immediate cause of death, extensive organic lesions were discovered in the alimentary canal, which could alone be attributed to the action of the tartar emetic. This fact will suggest a very important precaution to the practitioner, who may be called upon to treat a person labouring under a state of the system which will prevent the act of vomiting.^[302].

The symptoms produced by this salt will resemble those of a corrosive poison; and where vomiting is produced, it frequently happens that although the patient may be eventually saved, an irritability of stomach, so great as to cause the rejection of all aliments, will remain for a considerable period; and Dr. Male states that in the only case of poisoning by this salt which he had ever seen, the person was affected with violent convulsions, which returned at intervals for several weeks after recovery from the immediate effects of the poison.^[303] M. Orfila, after detailing several cases of poisoning by emetic tartar, concludes by saying that the general symptoms, upon such occasions, may be reduced to the following: a rough metallic taste; nausea; copious vomitings; frequent hiccup; cardialgia; burning heat in the epigastric region; pains of the stomach; abdominal colics; inflation; copious stools; syncope; small, contracted and accelerated pulse; skin cold, sometimes intensely hot; breathing difficult; vertigo, loss of sense, convulsive movements; very painful cramps in the legs; prostration of strength,—death.

Sometimes to the above symptoms is joined a great difficulty of swallowing; deglutition may be suspended for some time. The vomiting and alvine evacuations do not always take place, the necessary consequence of which is an increase in the violence of the other symptoms.

Antidotes.

The great indication to be fulfilled in a case of this description, is the ejection of the salt by vomiting. MM. Orfila and Berthollet rely very confidently upon the effects of bark, strong tea, infusion of galls, and other vegetable astringents, which have undoubtedly the power of decomposing the salt. They ought, therefore, to be employed as diluents to assist vomiting, but they are not to be considered as antidotes which can render this latter operation less indispensable.

Physiological action of emetic tartar.

M. Majendie has shewn by experiment, that if tartarized antimony be injected into the veins of a dog, the animal vomits, and has frequent stools; his breathing becomes difficult; his pulse frequent and intermitting; a great degree of disquietude, and tremblings are the precursory signs of death, which generally takes place within the first hour from the injection of the emetic tartar. On opening the body great alterations are perceived in the lungs; they are found of an orange or violet colour, have no crackling, are distended with blood, and of a tight texture. The mucous membrane of the intestinal canal, from the cardia to the extremity of the rectum is red, and strongly injected.

If, instead of thus injecting the emetic tartar into the veins, it be injected into the stomach, and the oesophagus is tied to prevent vomiting, M. Orfila informs us that the same alterations will be found after death. The very same effects will also arise from the application of the emetic tartar to the different absorbing surfaces, such as the cellular substances, &c.

Mr. Brodie^[304] has also thrown considerable light upon the action of this salt. He observes that the effects of emetic tartar so much resemble those of arsenic, which we have already described, and those of muriate of baryta, which will form a future subject of inquiry, that it would be needless to enter into a detail of the individual experiments which he made with it. When applied to a wound in animals which are capable of vomiting, it usually, but not constantly, operated very speedily as an emetic; in other respects he found no material difference in the symptoms produced in the different species of animals, which he had been in the habit of employing as subjects of experiment. The symptoms were paralysis, drowsiness, and, at last, complete insensibility; the pulse became feeble, but the heart continued to act after apparent death, and was maintained in action by means of artificial respiration; but never for a longer period than for a few minutes. Whence it would appear, that this poison acts by being absorbed, and that it directs a sedative influence upon the heart, as well as the brain, but that its principal action is on the latter. The length of time which elapses, from the application of the poison to the death of the animal, varies; in some instances Mr. Brodie found that it did not exceed three quarters of an hour, but in others, it was two or three hours, or even longer, before death took place. When a solution of emetic tartar was injected into the stomach of a rabbit, Mr. Brodie observed the same symptoms to take place, as when it was applied to a wound.

Organic lesions discovered by dissection.

Mr. Brodie, in his examination of animals poisoned by emetic tartar, sometimes found the stomach bearing the marks of inflammation, but at other times, its appearance was perfectly natural. In no case did he discover any traces of inflammation in the intestines. The reader must compare this account with that already given by M. Majendie, at p. 282.

1. Tests for the detection of emetic tartar.

1. The poison is in a solid form. Dissolve a portion of the suspected salt in about fifteen times its weight of boiling distilled water; if it be emetic tartar, the following reagents will identify it, viz.

(a) The hydrosulphurets will occasion a reddish-yellow precipitate, which is a combination of oxygen and antimony, proceeding from the emetic tartar; and of hydrogen and sulphur, from the reagent employed. If it be dried on a filter, and mixed with charcoal and the potass of commerce, it gives, by the action of heat, a cake of metallic antimony.

(b) Tincture of galls. This is regarded as the most sensible test of this salt, affording a precipitate of a curdled, dirty white colour, inclining to yellow.

(c) Lime water. This reagent produces a white precipitate, which is extremely thick, and is easily redissolved by pure nitric acid. In this case the lime forms an insoluble tartrate, and the tartrate of antimony, thus rendered insoluble, subsides along with it.

(d) Concentrated sulphuric acid gives a white precipitate, which consists of the oxide of antimony retaining a small portion of the acid. It redissolves in an excess of the precipitant.

(e) Vegetable extractive, occasions in the solution of this salt, a reddish-yellow precipitate, which has been found to consist of oxide of antimony, and a portion of vegetable matter.

If our attempts should fail to procure a solution of the salt by filtration, answering to the above reagents, we must rely upon the proof of metallic reproduction. Various circumstances may invalidate the action of our tests, such, for instance, as the ingestion of some vegetable infusion or decoction, especially that of galls, or yellow bark.

With respect to the other preparations of antimony, it is unnecessary to waste our time in their consideration; the precepts already given will afford the practitioner every requisite hint for the prosecution of the enquiry.

Copper.

This metal, with the exception of gold and silver, and perhaps tin, was known earlier than any other metal; but its applications were entirely confined to the arts. It was first discovered by the Greeks in the island of Cyprus, whence its name; and we learn from Homer, that even during the Trojan war, the combatants had no other armour but what was made of bronze, which is a mixture of copper and tin.^[305].

The external characters of the metal are too well known to require minute description. Its taste is styptic and nauseous; and the hands when rubbed for some time on it, acquire a peculiar and disagreeable odour. When melted, its specific gravity is 8·667; but after being hammered it is 8·9. It is only susceptible of two degrees of oxidation. If the protoxide be native, it is red; if artificial, orange coloured. The peroxide is black.

Copper, on exposure to a moist atmosphere, becomes tarnished, absorbs a portion of its oxygen, and passes into the state of an oxide, which shortly unites with the carbonic acid of the atmosphere, and forms a greenish carbonate of copper.

Metallic copper, perfectly pure, does not possess any deleterious properties. We have already cited instances^[306] sufficiently conclusive to establish this fact. It becomes, therefore, a subject of no little interest to enquire, under what circumstances it may become poisonous by combination. M. Orfila observes that it has been long maintained, that milk heated, or allowed to remain in vessels of copper not oxidized, dissolved a portion of this metal, and acted as a poison. Eller, a philosopher of Berlin, has, however, very clearly proved such an opinion to be incorrect. He boiled in succession, in a kettle well freed from verdegris, milk, tea, coffee, beer, and rain water; after two hours boiling, he found it impossible to discover, in any of these fluids, the least vestige of copper. M. Drouard has also shewn that distilled water, left for a month together on the filings of this metal in a glass bottle, did not dissolve an atom of it. The celebrated toxicologist above cited, after relating these important facts, concludes by observing, that the phenomena are very different, if, instead of pure water, we substitute that which contains a certain quantity of muriate of soda. Eller has demonstrated the presence of a very small quantity of copper in water, which contained 1/20th of its weight of muriate of soda, and which had been boiled in a brass kettle. This fact is of the highest importance, for it will explain the reason why highly seasoned aliments have proved deleterious, when cooked in vessels of copper. But we are indebted to Mr. Eller for a still more important discovery; he found that if, instead of heating a simple solution of common salt in copper vessels, the salt be previously mixed with beef, bacon, and fish, the fluid resulting from it does not contain an atom of copper.^[307] In relating this fact, M. Orfila observes, “however astonishing it may appear, it is quite correct, M. Eller was the first to announce it, and I have several times ascertained the truth of it; it is probable,” continues Orfila, “that the combination of several kinds of aliments destroys the effect of the solution of the muriate of soda; which consequently ought to render the cases of poisoning by aliments cooked in copper vessels, which are not oxidized, extremely rare.”

Copper combines with sulphur, and affords a black sulphuret.

Oxide of Copper.

By oxidation, copper becomes poisonous. The substance may be easily recognised by the change of colour which it produces in ammonia; this alkali will dissolve it instantly, and assume a beautiful blue colour. It is wholly insoluble^[308] in water. In oils and fatty matter it is easily and copiously dissolved at the ordinary temperature of the atmosphere. Such bodies also, when boiled in vessels of perfectly clean copper, facilitate their oxidation, especially if left to cool a few minutes before they are poured out.

Green Carbonate of Copper—Natural Verdegris.

This substance forms spontaneously on surfaces of copper and brass; it differs from the oxide in its green colour, and in effervescing with dilute sulphuric acid; with ammonia, however, it demeans itself in the same manner, and is likewise insoluble in water. It is poisonous.

From the above history of these substances the medical practitioner will easily perceive under what circumstances, and by what bodies, metallic vessels of copper may be rendered dangerous. The oxide and carbonate, formed in them, will easily dissolve in acidulous and oily aliments, whence it follows that all preparations of such food, if conducted in vessels whose surfaces have contracted this change will be liable to prove deleterious.^[309] If the vessels be perfectly clean, acid preparations may be safely boiled in them, but they must be poured out immediately, and not suffered to remain sufficiently long to allow the copper to become oxidized. To the formation of the oxide of copper, and to the acetic acid contained in the wine, vinegar, beer, and cider, M. Orfila attributes the production of the acetate which forms about the corners of the cocks in vessels containing these liquors. Upon the same principle the soda water sold in this town, in a draught, from the pump, is liable to metallic impregnation, as we have fully satisfied ourselves.

Equally important is it for the forensic physician to be acquainted with the various other sources from which copper poison may be derived. In consequence of the fact of the oxide of copper forming, with the acids, compounds of a beautiful green colour, the metal is often employed in cookery to impart a vivid hue to various articles; the sale of pickles, for instance, frequently depends upon the liveliness of their green colour; whence we find, in works^[310] on cookery, directions for ensuring such an effect, by boiling the pickles with copper coin, or by suffering them to stand for some time in vessels of that metal. In the third volume of the Medical Transactions of the College of Physicians we shall find an interesting history, related by Dr. Percival of Manchester, of a young lady who amused herself, whilst under the hands of the hair-dresser, with eating pickled samphire, of which she consumed two breakfast plates full; she shortly afterwards complained of great thirst, pain in the stomach, and a rash appeared upon her hands and breast. After an illness of nine days, during which she suffered severe vomitings, and tormina of the bowels, she expired. Upon examining the samphire, Dr. Percival found that it was very strongly impregnated with copper. In the preparation of confectionary, especially sugar-plums, and sweatmeats of a green colour, copper is very generally introduced, and many instances are recorded of their having proved highly deleterious. Catsup is also said to be occasionally impregnated with verdegris; and vestiges of this metal have been detected in the well known cordial, called Shrub.

In order to prevent the contingent dangers attendant upon copper vessels, they ought always to be tinned;^[311] and it is a very curious and interesting fact, that this latter metal, although it may cover the copper surface only imperfectly, will nevertheless protect us from its effects; for M. Proust has shewn that the superior readiness with which tin is oxidized and acted upon by acids, when compared with copper, will not allow this latter metal to appropriate to itself a single atom of oxygen.

But copper vessels, notwithstanding this fact, unless well tinned, should be dismissed from the service of the kitchen. The Senate of Sweden, in the year 1753, prohibited them entirely, and ordered that none but such as were made of iron should be used in their fleets and army.

Verdegris. Ærugo.

The verdegris of commerce is a compound mass, consisting of the acetate, and sub-acetate of copper, carbonate of copper, and copper partly metallic, and partly oxidized; it, moreover, contains the stalks of grapes and other extraneous matter. Boiling water dissolves it in part, and, at the same time, occasions in it a chemical change, by transforming one portion of the sub-acetate into the soluble acetate, and another, into an oxide of copper, which is precipitated. With cold water, verdegris demeans itself very differently; the acetate is dissolved by it, whilst that portion which is in the state of sub-salt remains suspended in the form of a fine green powder. Vinegar converts all the Ærugo into a soluble acetate. Sulphuric acid poured on its powder decomposes it with effervescence, and vapours of acetic acid are disengaged; a character by which this substance may be easily identified.

Blue Vitriol. Sulphate of Copper.
Blue Copperas—Roman Vitriol.

This salt occurs in crystals of a deep rich blue colour, and whose form is that of a rhomboidal prism; their taste is harsh, acrid, and styptic; on exposure to air they slightly effloresce, and assume a greenish hue. When treated with sulphuric acid, no effervescence occurs, a circumstance which at once distinguishes this salt from Ærugo.

Symptoms of Poisoning by the Salts of Copper.

The operation of these bodies, upon the human system, is betrayed by an acrid, styptic, coppery taste, in the mouth; nausea; head-ache; a dry and parched tongue; vomiting; coppery eructations; a cutaneous eruption; violent pains in the bowels; very frequent alvine evacuations, sometimes green, and often bloody and blackish; great and painful distention of the abdomen; small and irregular pulse; heat of skin; ardent thirst; difficult and laborious respiration; hiccup; syncope; cold sweats; convulsions—death. It does not, however, kill so speedily as arsenic, or corrosive sublimate.

Organic Lesions discovered on Dissection.

Where death has been speedily produced by a cupreous poison, dissection will generally discover inflammation, and even gangrene in the mucous membrane of the alimentary canal. Like other poisons of the corrosive class it will also be found to have occasionally extended its inflammatory action to all the coats of the canal, producing sloughs, easily detached, and leaving perforations. Dr. Male has also remarked that inflammation will sometimes be observed in the brain; but that this is not an universal effect of copper poison. It has been stated, that the fluids contained in the primÆ viÆ are, upon these occasions, very frequently tinged with a green colour.

Chemical Tests by which the presence of the preparations of Copper may be detected.

1. The suspected body is in a solid form.—We have already pointed out the characters by which the principal preparations of copper may be identified. Our judgment, however, upon these occasions will require that confirmation from experiment, which the following processes are calculated to afford.

A. By its reduction to a metallic state. If the copper presents itself in the form of an oxide, it may be easily reduced by heating it, in the usual manner, in contact with some carbonaceous matter; an earthen crucible will furnish the most convenient vessel for the occasion. If the substance has been scraped from a surface of copper, it is probably in the state of carbonate, (natural verdegris,) and may be calcined with charcoal in order to procure the metal. Should the substance in question be true Ærugo, we may at once heat it to redness in an earthen crucible, when, without the aid of any carbonaceous matter, we shall obtain metallic copper.

It may happen that the quantity of the above substances is not sufficient to allow their metallic reduction by calcination. In that case, we must proceed to obtain a solution; but since neither the oxide, nor the carbonate, is soluble in water, it will be necessary to bring them in contact with concentrated acetic acid, so as to obtain an acetate of copper; which will furnish the following indications with the respective tests.

a. A surface of clean iron. If dipped into the solution will become coated with metallic copper, and appear as if transmuted into that metal.

b. Ammonia. This test, when added in a quantity more than sufficient to saturate any excess of acid, will strike a beautiful blue colour; in the first instance we shall obtain a deep blue precipitate, but this will be redissolved by an excess of alkali. To detect the presence of copper, therefore, in pickles, it is only necessary to cut them into small pieces, and to pour liquid ammonia, diluted with an equal bulk of water, over them in a stopped phial: if the pickles contain the most minute quantity of this metal, the ammonia will assume a blue colour. In the same manner cupreous impregnations may be discovered in the various articles of confectionary above enumerated, and in those foreign conserves which are imported into this country, and usually sold in round boxes.

c. Sub-carbonate of Potass. By this re-agent a precipitate of a pale blue colour is produced.

d. Arsenite of Potass instantly occasions a copious precipitate in the acetate of copper, which is of a green colour, and is in fact an arsenite of the metal.

e. Triple Prussiate of Potass. This test gives a brown precipitate with a solution of verdegris, which is found to consist of prussiate of copper, and prussiate of iron; while the liquor contains an acetate of potass.

2. The suspected poison is mixed and combined with various alimentary substances.

We have in this case the same embarrassments to encounter, as those already noticed under the consideration of arsenic. Our tests may produce their respective precipitates, but they will present different colours according to the nature of the fluids with which the substance happens to be mixed; whence the circumstance of colour, so characteristic on other occasions, cannot be received as a satisfactory indication. In such a difficulty, we may collect the precipitates, and calcine them in a crucible with charcoal, in order to obtain the metal; or we may at once evaporate the whole of the alimentary mass, and submit it to a high temperature, by which means all the vegetable and animal principles, which can form a part of the liquor vomited, will be decomposed and converted into several volatile productions, and into charcoal; this combustible body will decompose the oxide of copper, and reduce it to its metallic state.^[312].

Nor is this process without its fallacies; it is often difficult to recognise the metal, dispersed as it necessarily must be, in small quantity, through a considerable mass of charcoal; in this case we are recommended by Orfila to place the product of the calcination in water, when in a short period, the copper, from its superior specific gravity will subside from the lighter particles of charcoal. But it would be still better to pour nitric acid upon the product of the calcination, and thereby to obtain a solution of nitrate of copper, which by filtration might be immediately prepared for the application of appropriate re-agents.

It merits notice, however, that in certain cases of poisoning by copper, no vestiges of the substance can be found in the matters voided from the stomach. In that case, Orfila directs that the mucous membrane of the stomach, and of the intestines, should be scraped off, dried, and submitted to the action of a strong heat in a crucible. “I have,” says this distinguished experimentalist, “twice obtained metallic copper, by calcining in this manner a portion of the membranes of the stomach of two dogs that I had poisoned with verdegris. This effect particularly takes place when the mucous membrane is of a bluish colour, hard, and strongly adhering to the substance of the stomach.”

Tin and its Muriate.

It is clearly established by the experiments of Bayen and Charlard,^[313] as well as by those of Proust,^[314] that this metal possesses no poisonous properties. Its muriate, however, has been shewn by Orfila to possess highly corrosive properties. It excites violent vomiting, great depression, and death, without convulsions. Its antidote is milk, which it speedily coagulates; and by chemical combination with it, the poison is rendered inert. On dissection, the stomach is said to have been found corrugated and indurated, and has been compared to tanned skin, but its colour is not altered.

As this substance is never likely to become an object of forensic interest, in this kingdom, we shall pass it over without farther notice.

Zinc.

The ancients were acquainted with a mineral to which they gave the name of Cadmia,^[315] from Cadmus, who first taught the Greeks to use it. They knew that when melted with copper it formed brass; and that when burnt, a white spongy kind of ashes was volatilized, which they used in medicine.^[316] This mineral contained a good deal of zinc; and yet there is no proof remaining that the ancients were acquainted with that metal. It has a brilliant white colour, with a shade of blue, and is composed of a number of thin plates adhering together; its specific gravity is 7·1. When strongly heated in a crucible, it quickly goes into fusion, absorbs the oxygen of the atmosphere, and burns with a beautiful white flame, inclining to green, and extremely brilliant. The oxide of zinc thus formed, is diffused through the atmosphere, and is there condensed into extremely light flakes of a beautiful white appearance. This oxide was formerly known under the fanciful names of nihil album; lana philosophorum, &c.

In its metallic state it is quite inert; but late experiments by Vauquelin and Deyeux, have proved that it is very easily acted upon by water, the weakest vegetable acids, some saline substances, and butter; a fact which is hostile to the proposal of employing this metal for the manufacture of culinary utensils.

White Vitriol. Sulphate of Zinc.

This salt occurs in masses, consisting of crystals which are four-sided prisms, terminated by four-sided pyramids. Their taste is styptic, metallic, and slightly acidulous. They are soluble in 2·5 times their weight of water at 60°, and in less than their own weight of boiling water, but they are quite insoluble in alcohol. Thus dissolved they redden the tincture of tournesol.

Symptoms of Poisoning by Sulphate of Zinc.

This salt, like tartarized antimony, from the high degree of emetic virtue which it possesses, generally proves its own antidote; still, however, it must be considered as a poison; for several cases are on record, where the most alarming symptoms, and indeed death itself, have been the effect of its ingestion. Metzger^[317] mentions the case of a woman, who accidentally ate a trifling quantity of a cake, into which White Vitriol had been introduced for the purpose of shortening the days of an old man. The woman died; but the intended victim escaped, after severe vomiting. M. Orfila has also related several cases of poisoning by this salt. The symptoms which presented themselves on these occasions were, an astringent metalline taste, a sense of constriction in the fauces, so distressing as even to excite in the patient a fear of suffocation; frequent vomitings; copious stools; pains in the epigastric region, extending afterwards over the whole abdomen; difficulty of breathing; frequency of pulse; paleness of the countenance, and coldness of the extremities.

We have lately heard of a case in which a noble lord swallowed a solution of white vitriol, which had been sent to him by mistake, for Epsom salts, to which it bears some analogy. Fortunately, however, the violent emetic effect which followed removed the poison from the stomach, and obviated any farther injury.

Organic lesions discovered on Dissection.

We have no well authenticated dissection of a human being who had died from the ingestion of this poison. The examination of animals^[318] who have been so killed has shewn nothing more than an inflammation, not very severe, of the membrane with which it had come in contact; sometimes dark blood is observed to be extravasated upon the muscular coat of the stomach and intestines.

Chemical processes for the detection of Sulphate of Zinc.

The chemist must remember that the White Vitriol of commerce always contains sulphate of iron, and sometimes sulphate of copper. When dissolved in distilled water it may be identified by the following re-agents; viz.

a. Potass, and Ammonia, precipitate an oxide of a greenish white colour, easily soluble in an excess of the latter of these alkalies. The oxide obtained by potass, being washed and dried, and calcined with charcoal, is revived, provided the temperature be very much elevated. It should be known, that if the salt has been previously purified, the above tests will occasion a white precipitate.

b. Prussiate of Potass produces a precipitate of a rather deep blue colour; which, consists of a mixture of the prussiates of zinc and iron. If the salt has been divested of all impurity, the precipitate will be white.

c. The Hydro-sulphurets instantly occasion a blackish precipitate, which, like the former, will be found to be a mixture of zinc and iron, in the state of an hydro-sulphuret. If the salt, however, is pure, its colour will be white with a tinge of yellow.

Silver.

This metal does not exert any influence on the living body; but its oxide in combination with nitric acid constitutes one of the most corrosive of all the metallic salts.

Lunar Caustic. Nitrate of Silver.
Lapis Infernalis.

The usual state in which this substance occurs is in that of small cylinders, having been cast into moulds for the purpose of imparting to it a form best adapted for the purposes it is designed to answer.

Its action on animal matter is highly caustic, and when introduced in any considerable quantity into the stomach, will induce death by corroding the texture with which it may come in contact. At the same time there is reason to believe that the whole, or part of its composition, may be absorbed; for we have many instances on record where the frequent repetition of this metallic salt, in small doses, has imparted a blue tinge to the skin, which can only be explained on the supposition that the oxide of the metal has been actually deposited in the rete mucosum^[319].

We are not aware that there is any modern case of poisoning by this salt^[320]. The medical practitioner, however, ought to know, that common salt, is its true antidote; indeed so completely does it decompose and separate it from water, that if a saturated solution of nitrate of silver be filtered through common salt, it may be afterwards drunk with impunity. M. Orfila, by a series of experiments, has shewn that if the muriate of soda be administered a very short time after the ingestion of lunar caustic, it will disarm it of its virulence by transforming it into an insoluble muriate, possessing no power of acting on the animal oeconomy.

Chemical processes for the detection of Lunar Caustic.

If a small portion of the salt can be procured it may be dissolved in distilled water, and immediately identified by the following tests.

a. Muriatic acid, or any soluble Muriate, will precipitate the muriate of silver, which is white, curdled, very heavy, insoluble in water, or nitric acid; but soluble in liquor ammoniÆ; when exposed to the air it acquires a black colour.

b. Potass, Soda, and Lime water, will occasion a precipitate of the oxide, of a deep brown colour.

c. Ammonia. This alkali will form an ammoniuret of silver, and in consequence of the solubility of this new product, little or no disturbance is occasioned by the test.

d. Arsenite of Potass. As all re-agents must be considered as reciprocal in their operation, it is hardly necessary to state that this is one of the best tests for nitrate of silver. See the history of its effects at p. 240.

If it should be necessary to discover the nitrate of silver amongst the fluids vomited, or those contained in the stomach of the deceased, we are very properly directed by M. Orfila to filter, and then assay by the appropriate tests; if, however, the different aliments should disguise the characteristic colour and appearance of these precipitates, we must proceed to desiccate and calcine them in order to obtain the silver in a metallic state.

The Concentrated Acids.

These must be regarded as the most terrible of all corrosive poisons. Their action is so immediate and energetic, as generally to destroy the membranes of the stomach, before their peculiar antidotes can be applied. Notwithstanding the obvious suffering they must occasion, and the facility with which they may be detected, such bodies have frequently, especially in France, been the instruments of suicide and murder; whilst in this country, we have had many lamentable illustrations of their deadly force, by their ingestion from fatal carelessness. In conformity with our general plan we shall proceed to consider the individual substances included under this general class, although the symptoms do not materially differ in the different kinds, nor are the indications of cure peculiar to any of them. There are however chemical characters which exclusively belong to each acid, with which the forensic physician must be accurately acquainted, in order that he may be enabled to detect their presence.

Oil of Vitriol. Sulphuric Acid.

This acid, when perfectly pure, exists in the form of a colourless liquid, without smell, and of an oily consistence; whence its popular name. Its specific gravity is 1·85, so that, in round numbers, it may be stated that an ounce, by measure, will weigh fourteen drachms. It acquires a brown tinge from the smallest portion of carbonaceous matter; mere exposure to the atmosphere is sufficient to effect this change, in consequence of the acid disorganizing and carbonating the vegetable and animal matter suspended in the air. This fact sufficiently explains why we generally find the acid of commerce of a brown colour.

Its taste is highly acid and caustic. So powerful is its affinity for water, that upon its admixture with this fluid, a heat, sufficiently great to boil water, may be produced. When exposed in its concentrated state to the air, it will imbibe at least seven times its own weight of water, and so rapidly as to have its weight doubled in a month. Straw, wood, and all vegetable substances, when immersed in the sulphuric acid, without heat, are disorganized, softened, and blackened, and there is separated from them a certain portion of charcoal. Like the other mineral acids, the Oil of Vitriol has never been obtained in an insulated state without water; according to the latest views of Sir H. Davy, the composition of the strongest acid may be expressed as follows. Sulphur 30, oxygen 45, water 17.

Symptoms of Poisoning by Oil of Vitriol.

An extremely austere, acid, and burning taste; a painful heat in the fauces and throat, along the oesophagus, and in the stomach; excruciating pain; nausea, and excessive vomiting; at one time the fluid vomited is as black as ink, at another reddened by arterial or venous blood, producing in its passage through the throat, the most intense pain, accompanied with a sensation of bitterness quite intolerable; if, by chance, a portion of it should fall on the hearth or pavement, or on any other calcareous substance, it will denote its true nature by an effervescence; constipation, or sometimes bloody stools; gripes and excruciating pains over the abdomen, with a tenderness of these regions, so exquisite as not to allow the slightest pressure without torment; pains of the breast; difficulty of breathing; extreme anxiety; the pulse becomes frequent, small, contracted, and irregular; shiverings; great restlessness, dejection, and agitation; convulsive motions of the countenance; sometimes a cutaneous eruption betrays itself. Amidst all these symptoms, the intellectual powers remain unobscured. The parts about the fauces, the uvula, &c. having lost their vitality, slough, and become detached, which occasion an indescribable fetor of the breath, while they produce a perpetual cough, and the voice becomes so altered, that it resembles the sounds of a person labouring under croup.

As this substance destroys life by simply acting as an escharotic, it is not difficult to anticipate the disorganization which dissection will display. The extent of the lesion, however, must in every case depend upon the quantity and degree of concentration of the acid, the state of the stomach in relation to its alimentary contents, and other incidental circumstances not to be exactly appreciated. The mucous membrane of the mouth, the tongue, and oesophagus, will in general be found destroyed, and converted into a pulp.

Antidotes.

The great indications to be fulfilled in this distressing case, is the immediate dilution, saturation, and expulsion of the poison. Copious draughts of water, holding calcined^[321] magnesia in suspension, should be administered without any loss of time. If this is not in readiness, soap and water should be administered; mucilaginous drinks, milk, and even warm or cold water, in the absence of more eligible potations, should not be neglected. It must be never forgotten, exclaims Orfila, that success upon these occasions depends upon the activity of the practitioner; the delay of a few moments will entirely change the fate of the patient, as the sulphuric acid destroys the texture of the organs with a fearful celerity. After having thus neutralized the caustic, it will be our duty to obviate the effects it may be likely to occasion; the lancet must be used with boldness, and the detraction of blood repeated at short intervals; at the same time emollient clysters may be advantageously injected.

Chemical processes for the detection of Oil of Vitriol.

In the pure state, there can exist no difficulty in identifying it; its specific gravity, and its action on vegetable matter, will, without any other tests, be quite sufficient to fulfil our object. If heated with metallic mercury, it will disengage sulphurous acid gas; and if united with lime, a sulphate of lime will be produced, which the chemist may easily recognise by dissolving a portion in distilled water, and assaying the solution by muriate of baryta, which will produce with the sulphate a precipitate, insoluble in nitric acid. By the last mentioned tests we shall be enabled to detect the presence of sulphuric acid, in whatever state of complication it may happen to exist with alimentary matter.

Nitric Acid.

This acid, when pure, assumes the form of a limpid fluid, emitting white fumes of a suffocating odour; its taste is highly acid, and corrosive; and it is at once distinguished from all other acids, by its tinging the skin indelibly yellow. When of the specific gravity 1·5 it contains 74·895 per cent of dry acid, (whose ultimate elements are one proportional of nitrogen, and five of oxygen) the complement 25·105 parts, is water.^[322] It is decomposed with violent action by all combustibles, and when mixed with volatile oils it causes their inflammation.

From the facility with which this acid undergoes decomposition, it is rarely found in commerce in a colourless condition; indeed the action of light is sufficient to impart a tawny tinge to it; when this change has proceeded to such an extent as to render the acid orange coloured, it is called Nitrous acid, or, in the language of the arts, aqua fortis, although in a chemical point of view, such a nomenclature is incorrect, for it is nothing more than nitric acid, holding nitrous acid gas loosely combined.

Symptoms of Poisoning by Nitric Acid.

This acid has been so frequently swallowed in France, for the purpose of committing suicide, that it has enabled the pathologists of that country to afford a very satisfactory account of its operation, and effects. To M. Tartra we are particularly indebted for a very full and interesting investigation of the subject, and we shall avail ourselves upon the present occasion, of the many facts and observations with which his treatise^[323] abounds. In describing the symptoms occasioned by the ingestion of this acid, M. Tartra establishes four different gradations, viz. 1. When the death is speedy, for it is never sudden, it commonly takes place from the primary effects in about twenty-four hours, varying from six to forty-eight hours. 2. When it proves fatal from its secondary effects, at different intervals, from fifteen days to several years. 3. When death does not take place, but the recovery is imperfect. 4. When a perfect cure is sooner or later obtained. The first case is illustrated by the following example, which will serve to convey a very just idea of the progress and intensity of the symptoms. “A man, driven by distress to commit suicide, under the greatest agitation of mind, and upon an empty stomach, swallowed, at a draught, two ounces of concentrated nitric acid. Instantly he was seized with the most excruciating pains and agitation, and could not lie in bed, but rolled himself upon the floor. Vomiting came on, accompanied by a general sensation of coldness, especially in the extremities. Every time he vomited, the matter effervesced upon the pavement. A solution of soap and oil was administered to him, and in two hours he was brought to the hospital, often having vomited, and stopped on the road to drink. On his arrival, he had emollient drinks, especially linseed tea, in great abundance. He was in continual agitation, and his countenance was greatly altered. He now vomited every instant a blackish glairy matter; he opened his mouth easily, and his tongue was white, with a tinge of yellow; he complained of acute pains in his mouth, along the oesophagus, and in his stomach. His belly, slightly tense, could not bear the slightest pressure, without great torment. The surface of the body was cold; the pulse small and frequent; he had hiccup, and the respiration was laborious.

His symptoms increased. He uttered sighs and lamentations; his limbs became icy; a cold sweat covered his whole body; his pulse was scarcely perceptible; the pain was constant; still he could rise and make continual but useless efforts to quench his thirst, and satisfy his urgent desire to void urine, and go to stool. He continued in this state during the night; the matters vomited became more clear, and of a yellow colour. He at last made a few drops of urine. The shocking appearance of his body already resembled that of a corpse, but he retained his senses, and was speaking when he expired, nineteen hours after swallowing the acid.” The burning heat and pains which are commonly the immediate effects of the ingestion of this acid are very variable in their intensity and duration, and M. Tartra observes that, in general, they are not in proportion to the quantity or strength of the acid swallowed. It often happens that persons who have taken only a small dose, are seized with the most excruciating and dreadful pains, and some of those who have swallowed a great quantity, two or three ounces for example, have had scarcely any suffering, but remained very tranquil. In the first case, the patients either recover, or survive a long time; in the second, speedy death is almost always the consequence; thus a young man of twenty died in twenty hours, without any agitation or signs of acute pains. On opening the body, the highest degree of disorganization appeared, perforations of the stomach, and great effusion of its contents into the abdomen. The second variety of the progress and termination of poisoning by nitric acid, exhibits, at first, the same phenomena as the preceding; but less alarming symptoms succeed by degrees; after some months, the inner membrane of the alimentary canal detaches itself in portions, the patient falls into a marasmus, and dies. We are here presented with a case of consecutive poisoning, see page 147.

The third termination is in imperfect recovery. A slow and progressive amendment ensures the safety of the patient; but there still remains some complaint; obscure pains in the throat, and especially in the epigastric region; habitual constipation, occasional vomiting, and increased sensibility of the stomach, so that it can only support light nourishment and bland liquors; in short, they continue invalids during the rest of their lives; they are subject to repeated and even habitual indispositions, and sometimes to pain and insupportable heat of the stomach; but they are able to follow their occupations, and long survive their poisoning.

The total disappearance of the symptoms produced by swallowing nitric acid; or complete and absolute recovery without leaving any consequences, is the last variety of termination.

Organic lesions discovered on Dissection.

Tartra has furnished us with the following interesting account of the dissection of those who have died of the primary effects of nitric acid. The external appearance of the body presents no alteration; every part is sound and natural, and possesses, in a certain degree, the firmness and freshness of life. The epidermis of the margins of the lips has commonly an orange colour, more or less deep. It seems burnt and easily separates. Sometimes yellow spots are discovered on the hands and other parts of the body, caused by the contact of the acid. A yellow fluid, in some cases very abundant, flows from the mouth and nostrils, and the belly is considerably distended with air. The alimentary canal is remarkably affected. All the internal membrane of the mouth is burnt, and has sometimes a white colour, but is more commonly yellow; it is separate in some places, and adheres in others. The teeth are often loose, and have a very marked yellow colour at their crown. The mucous membrane of the pharynx exhibits the same change, or is in a state of inflammation of a dirty red colour. The whole extent of the oesophagus is lined with a dense mass of a fine yellow colour, dry on its surface, unctuous and greasy to the touch, and which seems to be formed both of the mucous membrane, altered in a particular manner, and of the albumen contained in the viscid fluid which exudes from the membrane of the oesophagus, solidified by the nitric acid. This lining adheres in very few points, and is easily detected from the other membranes of the oesophagus, which are brown and blood-shot. When the stomach is not perforated, it has commonly a considerable size; externally, its membranes are slightly and partially inflamed, but very much towards the pylorus and beginning of the duodenum. Its colour is faded, livid, of a yellowish green, with large gangrenous spots. It adheres every where to the neighbouring parts, the diaphragm, liver, spleen, and transverse arch of the colon, by means of a concrete lymphatic exudation; its sides, which are thin and yellow in some places, and thick and black in others, exhibit net-work of dilated blood-vessels filled with black coagulated blood. Often there are several points of the stomach dissolved, and ready to burst with the slightest touch; it contains a great quantity of gas, which has a peculiar smell, resembling that of bitter almonds; it also very commonly contains a great quantity of yellow matter, of a pultaceous consistence; the substance of the stomach is generally swelled in some places, and deeply marked with black, without being dissolved; this effect is most remarkable at the great end, into which the acid seems to fall by its weight; the rugÆ of the stomach are very brown, and are reduced to a mucilaginous consistence. The other parts of the alimentary canal exhibit the same organic lesions, although the phenomena have less intensity in proportion as the part is more distant from the stomach.

In those cases where the stomach is found perforated, its bulk is very small; the holes commonly occur in the large and small extremities; their form is circular, and their edges thin, and as if dissolved. The urinary bladder contains no urine, although the patient have not discharged any.

The appearances upon dissection of those who die of the secondary effects are entirely different from those above described. It would be difficult to find an example of greater emaciation, more advanced consumption, or more disgusting form. Nothing is equal to the degree of withering, and decrepitude of the whole organs; their colour is faded; the internal cavities do not contain the usual serum; the cellular and muscular systems are almost annihilated; the bones become dry, as in persons of advanced age, and break with extraordinary facility; but these changes are general and secondary, and depend upon local organic derangement of the alimentary tube. The stomach and whole intestinal canal are contracted to an extremely small size; the intestines are not larger than the little finger, sometimes not exceeding a thick writing quill; their coats are very thick, their cavity almost obliterated, and containing only a little mucosity. The stomach, which often resembles a portion of a small intestine, appears sound externally, and only presents some adhesions to the neighbouring viscera; internally, the most remarkable change is the contraction of the pylorus, the passage through which will scarcely admit a probe; and the membranes of the stomach itself are so thickened and compacted around it, that they have lost all their natural suppleness. On the internal surface, there are irregular spots, or rather smooth and red places, which seem to be covered with a regenerated mucous membrane, less villous than that which had been destroyed by the action of the acid; these cicatrices are particularly large and numerous in the great end of the stomach, and around the circumference of the pylorus.

Chemical processes by which the presence of Nitric Acid may be discovered.

If the acid be in any quantity, and without mixture, there cannot exist any difficulty in demonstrating its presence. If added to copper filings, there will be a copious disengagement of orange-coloured fumes, and a nitrate of copper of a blue colour will remain, as the product. If it be saturated with potass, we shall at once obtain by due evaporation the well known substance, nitre; this salt will announce its nature by deflagrating with charcoal or sulphur. This latter test is the one we must employ for the detection of nitric acid, when mixed with vinegar, and other liquids. Where the acid has combined with the animal matters with which it may have come into contact, they must be boiled for an hour in a solution of pure potass, when the solution will assume a reddish appearance; this must be filtered, and evaporated in a capsule of porcelain, when the mass so obtained will leave a residuum of nitrate of potass.

Dr. Marcet, in a paper just published in the Philosophical Transactions,^[324] on the composition of sea water, employed a new mode of assaying the solution for nitric acid, and for which he acknowledges himself indebted to Dr. Wollaston. Having concentrated the bittern in a glass vessel, until it began to deposit solid matter, he added sulphuric acid and gold leaf, and boiled the mixture; the gold leaf was not in the least acted upon, nor was any smell of nitric acid perceived; but on adding the smallest quantity of nitre to the same mixture, the gold was dissolved, and the smell of aqua regia instantly perceived. The rationale of the experiment is obvious, gold, although insoluble in muriatic acid, is instantly dissolved on the addition of nitric acid, in consequence of the developement of chlorine.

Spirit of Salt. Muriatic Acid.

The liquid acid, of which we are about to treat, is a solution of muriatic acid gas in water; when of the specific gravity 1·16, according to Davy, it contains 32·32 per cent. of the gas, which recent experiments have proved to be a compound of Chlorine (oxy-muriatic acid) and hydrogen, in equal volumes. It has accordingly received a name expressive of its composition, and is called Hydro-chloric acid. Its odour is strong and peculiar; when exposed to the air it emits white fumes; its taste is intensely sour and caustic; it is, however, the weakest of the three mineral acids, and no remarkable elevation of temperature is produced by dilution. It readily combines with potass, soda, &c. and furnishes a class of salts which may be easily recognised by their characters.

Symptoms of Poisoning by Muriatic Acid.

As the effects of muriatic acid do not differ from those which have been described, as the consequences of poisoning by the other mineral acids, it will be unnecessary to enumerate them. Orfila, however, remarks, that the patients who have swallowed a certain quantity of it, emit, in the first moments of the accident, a thick smoke of a white colour, and very pungent smell.

Chemical processes for the detection of Muriatic Acid.

This acid, in its free state, immediately announces its nature by the fumes which it emits. When the acid, however, exists in a more questionable shape, as in the matter vomited by the patient, or in that found in the digestive canal after death, it will be necessary to saturate the liquid part with pure potass, and to boil it for some time, when we shall obtain a fluid, from which the nitrate of silver will throw down a dense precipitate. By evaporation, we shall obtain a crystallized muriate, which may be identified by the following tests: 1, When concentrated sulphuric acid is poured upon it, a brisk effervescence is immediately occasioned, and the muriatic acid is disengaged in the form of white vapours, which are thick, and of an excessively pungent smell. 2, If instead of employing concentrated sulphuric acid, this acid be used in a state of dilution, and the muriate be mixed with some substance which easily yields its oxygen, the muriatic acid will be decomposed, its hydrogen, combining with the oxygen so as to form water, while the chlorine will be disengaged, and by its pungent and peculiar odour at once announce the nature of the acid under examination.

This salt occurs in small crystals, whose form is that of a four sided prism. It is extremely acid to the taste, so that by applying the tongue to one of its crystals, its nature may be immediately discovered. It dissolves in twice its weight of cold, and in an equal weight of hot water; it is also soluble in boiling alcohol which takes up about half its weight; the solutions act powerfully on the vegetable colours, and at once denote their acid properties. On account of the strong resemblance which the crystals of this acid bear to those of sulphate of magnesia, or Epsom salts, many fatal accidents have occurred. We are not aware that it is ever purchased, in retail, for any other purpose than as a detergent, to clean the tops of boots; in the large way, it is an article of extensive trade with the calico printers. Its salts^[326] are likewise employed for various purposes in the arts.

Amongst the many schemes which have been proposed to secure the public against the possibility of mistaking this acid for Epsom salts, there does not appear to be one which admits of successful application; nor are we able to propose any test of discrimination which is not far inferior in accuracy and convenience, to that which is afforded by the mere taste of the crystal; indeed we cannot understand how so acid a solution can be swallowed, without an immediate discovery.

Symptoms of Poisoning by Oxalic Acid.

From the history of the many cases on record, it appears that this acid produces all the grievous symptoms, which characterise the action of a corrosive poison; its operation upon the stomach is similar to that of any other powerful acid; and dissection displays the same destruction of parts, as that we have already described under the consideration of the mineral acids.

Antidotes.

We should endeavour to form as quickly as possible an insoluble oxalate of lime; copious draughts of lime water, or magnesia and water, should be administered; and vomiting immediately excited.

Chemical tests for the detection of Oxalic Acid.

If any of its crystals can be obtained, we shall be immediately able to identify them. They dissolve very readily in water, and since the oxalic has a greater affinity for lime, than any other acid, and forms an insoluble salt with it, we have thus a ready test of its presence, for it will decompose all the calcareous salts, not even excepting the sulphate.

Boiling Water.

Many cases are recorded of the death of children from the ingestion of boiling water; an accident which will be always liable to occur, as long as the peasant allows his family to quench their thirst by drinking the cold water through the spout of the tea kettle. It has been very generally supposed that fatal effects have, on these occasions, supervened the high state of inflammation produced in the Æsophagus and stomach by the boiling liquid. Dr. Marshall Hall has, however, lately published a very interesting paper on this subject, in the twelfth volume of the Medico-Chirurgical Transactions; from which it would appear, that the patient, under these circumstances, actually dies of suffocation as in croup; and that the boiling water is arrested in its progress to the stomach by the convulsive action of the muscles of the pharynx. In passing, however, to the posterior part of the mouth, it scalds the epiglottis, and glottis, which afterwards become more and more swollen, until at length the rima glottidis, or orifice into the larynx, becomes completely obstructed. Here then we have a new instance in which the operation of laryngotomy, or of tracheotomy, may be performed with the effect of preventing impending suffocation, and perhaps of saving life. Dr. Marshall Hall relates four cases in illustration of this interesting fact; of which one recovered from imminent suffocation immediately after screaming^[327]; two died from suffocation, one 10, the other 17 hours, after the accident; the fourth was completely relieved by the operation of tracheotomy, and survived 34 hours, but died, exhausted by the irritation produced by the primary affection.

Melted Lead.

An instance stands recorded in the history of the destruction of the Eddystone-light house, by fire, where a quantity of melted lead fell into the mouth, and was swallowed by a person who was attentively watching the conflagration. It is very singular, that this man lived many days after the accident; a fact which at least shews what extensive injury the stomach will occasionally sustain, without the immediate destruction of life. The lead taken out of the stomach after death, in this case, weighed exactly seven ounces, five drachms, and eighteen grains.^[328]

The Caustic Alkalies.

These bodies are distinguished by a highly corrosive and peculiar taste; they change the blue^[329] juices of vegetables to a green, and the yellow to a brown; they are soluble in water, and have the power of imparting the same property to oils, by combining with them, and thus forming saponaceous compounds. With the different acids they constitute peculiar salts. When applied to the flesh of animals they act as powerful caustics, destroying its texture, and ultimately dissolving it; they are accordingly arranged with great propriety under the head of corrosive poisons.

There are three^[330] alkalies—potass, soda, and ammonia. To the two former the epithet fixed has been applied, since they require a very high temperature for their sublimation; while to the third, that of volatile has been assigned, because, when uncombined, it exists in a state of gas. Potass, as it was considered the product of vegetation, has received the name of the vegetable alkali, while soda, as the base of rock salt, has been distinguished by that of mineral alkali. The distinctions, however, originally established by Avicenna, must now be abandoned, for they have not the slightest foundation in truth; potass, so far from being the exclusive product of vegetation, exists as a constituent part of the Granite, which forms the foundation of our globe; it has also been discovered in the Pumice stone; in some minerals of the Zeolite family; in the Leucite; in the aluminous ores of La Tolfa, &c. and, although potass is undoubtedly procured by lixiviation from the ashes of burnt wood, and other vegetable substances, yet there is ample grounds for supposing that the living plant receives it from the soil in which it vegetates.

Potass, or Potash—

Liquor PotassÆ—Potassa Fusa, or Kali Causticum—Lapis Infernalis—Causticum commune acerrimum. Potassa cum Calce—PotassÆ Sub-carbonas, or Salt of Tartar—Potash—Pearl ash.

Potass is rarely met with in a pure form, except in the laboratory of the philosophical chemist, and is therefore not likely to become an object of judicial enquiry; but in various states of mixture, as presented in the different preparations above enumerated, it may become the accidental, as well as criminal means of poisoning; we shall therefore consider the chemical history of these different preparations separately, and then describe the symptoms which they generally occasion.

Liquor PotassÆ.

This may be considered as a nearly pure solution of potass, although, as it is usually prepared, it contains small portions of muriate and sulphate of potass, silica, and lime. It is a limpid, dense, colourless solution; when rubbed between the fingers it feels soapy, in consequence of a partial solution of the cuticle. As it constitutes a medicine in common use, and, moreover, forms the basis of many quack medicines, as well as of those preparations which are sold under the name of Depilatories, it may readily become the accidental instrument of mischief.

Chemical Tests for its detection.

There cannot exist any difficulty in this investigation; its highly alkaline characters will be immediately announced by its effects on the vegetable test papers, and by its power of saturating acids; while the particular species of alkali may be readily identified by the following reagents.

(a) Carbonic acid; or water saturated with the gas. This will not produce any^[331] disturbance in the solution of potass; a fact which at once serves to distinguish this alkali from the earths, baryta and lime.

(b) Deuto-muriate of Platina occasions a canary-yellow precipitate, consisting of the deutoxide of platina, potass, and muriatic acid; as this precipitate is, to a certain extent, soluble in water, the test may fail through dilution. With soda, this reagent will not occasion any precipitate, a fact which depends upon the solubility of the triple salt formed, and affords an easy method of distinguishing the fixed alkalies from each other.

(c) Tartaric acid. If an excess of this acid be added, we shall obtain crystals of a bi-tartrate; a phenomenon which will not take place if soda be the alkali employed.

Potassa Fusa, or Kali Causticum.

This substance, which occurs in sticks, or cylinders, is an extremely caustic and deliquescent substance; it is principally employed in surgery, to establish an ulcer; or, instead of incision, to open a tumour. See Pharmacologia. As it differs from potass, only in the degree of purity, it is unnecessary to offer any farther remarks.

Potassa cum Calce.

This is a mixture of the preceding substance with lime, which is added with a view to diminish the deliquescent property of the alkali, and thus to render it more manageable as an escharotic. There will be no difficulty in separating these ingredients. Their different solubilities will furnish an easy mode of effecting it to a certain extent, and we may then precipitate the remaining portion of lime, by carbonic acid.

Sub-carbonate of Potass—Salt of Tartar—Pearl-ash—Potash.

Although potass becomes comparatively mild, by its union with carbonic acid; yet the present preparation retains so much causticity as to render it poisonous, if administered in any considerable dose. Plenck reports a case of this kind, where a patient having swallowed an ounce of salt of tartar, was shortly afterwards seized with a violent vomiting, which continued for forty-eight hours, followed by a violent inflammation of the stomach; from which, however, he ultimately recovered.

Symptoms of Poisoning by any of the above preparations of Potass.

A styptic, urinous, and caustic taste; a severe heat in the throat; violent vomiting, generally of alkaline matter, turning the syrups of violets green, and where the alkali has been in the state of carbonate, effervescing with acids; sometimes the matter thus ejected is mixed with blood; copious alvine evacuations; severe pain in the epigastric region; excruciating tormina of the bowels; depravation of the intellectual faculties, and death. It will be easily perceived that the above symptoms merely indicate the operation of a corrosive poison. They offer no characteristic peculiarities which can enable us to decide upon the particular substance that has been swallowed, unless, indeed, the matter vomited can be submitted to examination.

From the experiments of Orfila, it appears that vinegar, diluted with water, is the remedy which can be administered with the greatest success, where any preparation of this alkali has been swallowed in a poisonous dose.

Organic lesions discovered on dissection.

In consequence of the peculiar action of this alkali upon animal matter, we shall generally find the stomach perforated, and its coats extensively dissolved. We shall moreover discover the usual indications of violent inflammation in this viscus, as well as in the intestines.

Soda.

We have already stated by what chemical reagents this alkali may be distinguished from potass; it only remains for us to observe that its physiological action, the symptoms arising from its ingestion, and the organic lesions discovered on dissection, are strictly analogous to those we have described as the effects of potass.

Ammonia, and its Carbonate.

Ammonia, in its uncombined state, exists in the state of gas, and is incapable of application; its affinity, however, for water, enables it to combine with that fluid, and to form liquid ammonia, (Liquor AmmoniÆ) in which state it is useful in medicine, and in the arts. This solution is colourless; its taste extremely caustic; and its odour strong, pungent, and peculiar. Exposed to the action of heat, the ammoniacal gas is driven off, and may be recognised by its characteristic odour, as well as by its effects upon moistened turmeric paper. When brought into contact with muriatic acid, it will form dense white vapours, consisting of muriate of ammonia. A most elegant and sensible test for ammoniacal gas is afforded by a mixed solution, consisting of arsenious acid and nitrate of silver; these substances when mixed in solution do not occasion the least disturbance in each other, for reasons already explained, (see page 240) but upon spreading a portion of the liquid upon glass or paper, and bringing ammoniacal gas into contact, a beautiful yellow cloud immediately diffuses itself over the surface of the solution.

Sub-carbonate of ammonia occurs in solid, white, semi-transparent masses, of a highly pungent and ammoniacal odour. Its chemical composition has been found to vary materially according to the circumstances under which it has been prepared; Mr. R. Phillips, who has made some highly interesting experiments upon this subject, considers the sub-carbonate to be a sesqui-carbonate, composed of 3 atoms of carbonic acid, 2 atoms of ammonia, and 2 of water. By long exposure to the air, its pungency is lost, and it is converted into an inodorous carbonate.

Symptoms of poisoning by Ammonia.

Cases wherein death has been produced in a few minutes, from the ingestion of liquid ammonia, stand recorded on the authority of Martinet, Huxham, Haller, and other physiologists. In such cases the lips, tongue, and fauces are described as being burnt by the causticity of the fluid; while hemorrhage of the intestines marks the organic lesions which it occasions. The nervous system would appear also to suffer greatly, at the same time that the abdominal organs are affected with violent inflammation.

The Caustic Alkaline Earths.

Under this division, we have to consider the two earths, Lime and Baryta; both of which are highly corrosive, although they essentially differ from each other in their physiological action. In this respect they may be compared to corrosive sublimate and arsenic, and offer an additional illustration of the imperfection of the present classification; for while lime acts as a local caustic upon the parts with which it comes in contact, baryta will require, for its action, to be absorbed and carried into the current of the circulation.

Quick Lime.

This earth is of a white colour, and of a hot caustic taste; with acids it forms peculiar salts; a fact which we shall shew affords the most decisive means of identifying its presence. It changes vegetable blues to a green, and reddens turmeric; it is capable of fusion; so great is its affinity for water, that it will absorb and solidify one third of its weight of that fluid, and yet remain perfectly dry. The heat, therefore, that is evolved in the process of slacking lime, evidently proceeds from the water, which yields its caloric, as it passes from the liquid to the solid state.

Symptoms of poisoning by Lime.

It is perhaps the least energetic of the corrosive poisons; and yet, when taken in any quantity, it will produce nausea, vomiting, colics, frequent stools, and all the symptoms which characterise, or are complicated with, inflammation of the stomach and intestines.^[332] Lime in combination with carbonic acid is not considered as poisonous.

Organic lesions discovered on dissection.

In examining the body of an animal that has been killed by caustic lime, we shall find the mucous membrane of the stomach reddened, and evincing marks of inflammation in those parts which have been in contact with it.

Tests for the detection of Quick-lime.

We may proceed, if the substance be free from mixture, to obtain a solution of the earth in distilled water, and to assay it by the following reagents.

(a) Carbonic acid, and the soluble alkaline sub-carbonates produce a copious white precipitate, which is soluble in an excess of carbonic acid. The carbonate of lime, of which this precipitate consists, is also decomposed by muriatic acid, with effervescence, a soluble muriate remaining.

(b) Oxalic acid, and oxalate of ammonia. They precipitate lime-water of a white colour, and the resulting oxalate is not soluble in an excess of acid.

(c) Sulphuric acid. This acid does not precipitate lime water, since the sulphate of lime formed does not require more than 300 parts of water to dissolve it. Whereas, says M. Orfila, the smallest quantity of an exceedingly diluted solution of baryta becomes instantly turbid on the addition of that acid, because the sulphate of baryta is insoluble in several thousand times its weight of water. By this test, therefore, we are at once enabled to distinguish lime-water, from barytic water.

Baryta, and its Salts.

Baryta, like lime, is a solid, heavy, alkaline earth, having an acrid and peculiar taste; and turning the syrup of violets green, and the juice of turmeric red. When perfectly calcined, it absorbs water very rapidly, disengaging at the same time a quantity of caloric; the phenomenon is similar to that of slacking lime, and admits of the same explanation. It dissolves in about 20 parts of water, at the temperature of 60°; but boiling water will dissolve half its weight of this earth, part of which will crystallize on cooling.

Muriate of Baryta. This salt crystallises in square plates, or four-sided prisms; its taste is acrid and pungent. It dissolves in 2½ parts of distilled water at 60° Fah. The solution is limpid and colourless, and has been employed in medicine, as a remedy in scrofula, cancer, some forms of syphilis, and in hectic fever connected with ulceration. Dr. Johnstone says that he has seen a delicate female take as much as thirty drops of a saturated solution of this salt, repeatedly, without nausea; whence he concludes that it would require at least 2 or 3 drachms to do mischief.^[333]

Symptoms of poisoning by Baryta.

All the soluble compounds of this earth are poisonous, especially the muriate; which, whether injected into the veins, introduced into the stomach, or externally applied to an abraded surface, will occasion death in a very short period. We are not aware that any case stands recorded of poisoning by baryta. Orfila^[334] and Brodie^[335] have, however, investigated the symptoms which this poison produces on animals, and they appear to be analogous to those occasioned by the ingestion of arsenic. The muriate, on account of its greater solubility, would appear to be much more active than the pure earth, or its carbonate.

Physiological action of Baryta.

Barytic poisons require to be absorbed before they act on the system; they may therefore destroy by external application, although it would appear that, unlike arsenic, they act sooner when internally administered. Mr. Brodie thinks that the muriate of baryta occasions death by acting upon the brain and the heart; at the same time it exerts a local action, and corrodes the viscus with which it comes into contact.

Antidotes.

It has been shewn by the experiments of Orfila, that the soluble sulphates, as Glauber or Epsom salts, by converting the baryta into an insoluble sulphate, will act as antidotes to its virulence. In the first instance, therefore, it will be prudent to produce this chemical decomposition in the poison, and then to expel it, as quickly as possible, by emetics.

Where the pure earth, baryta, or its solution in water, is presented for our investigation, it may be identified by the following reagents.

(a) Sulphuric acid, and the soluble sulphates. These bodies precipitate from the barytic solution, a white sulphate of the earth, insoluble in water, and nitric acid.

(b) Carbonic acid gas, and the alkaline sub-carbonates, produce in it a white carbonate of baryta.

(c) Muriatic acid combines with baryta, and furnishes a salt which is capable of being identified by numerous reagents. M. Orfila has furnished us with the following satisfactory compendium of its habitudes. “A salt which does not redden the tincture of tournesol, which does not turn the syrup of violets green, which is not precipitated by the alkaline hydro-sulphurets,^[336] nor by ammonia; but which, on the contrary, is precipitated by the sub-carbonate of ammonia, soda, or potass; which is not soluble in concentrated alcohol; which furnishes, with the sulphate of potass, or the sulphuric acid, a white precipitate insoluble in water and in the nitric acid, and which gives with the nitrate of silver a curdled precipitate of muriate of silver, likewise insoluble in the nitric acid, can be no other than the muriate of baryta.”

But it may happen, that the above salt is so mixed with alimentary matter, as to defy the action of the tests; in this case we must endeavour to obtain from it the pure earth, by precipitating the suspected fluids by the sub-carbonate of ammonia; when a carbonate of baryta will fall down, which must be dried on a filter, and calcined with charcoal.

Cantharides. Spanish Flies—Blistering Flies. (Cantharis Vesicatoria, Sp. 1, of Latreille.)^[337]

Cantharides are imported into this country in their entire state, and are so kept in the shops; their form and general appearance are too well known to require description, and they will rarely become the objects of inquiry; in powder, however, they may be presented to us for investigation, and it is therefore essential that the forensic physician should be acquainted with the appearances which they assume in the state of disintegration. This powder has a greenish colour, tinged with grey, and abounding with shining points of a very beautiful green colour, and which may be recognised in whatever state of division the powder may exist, even after it has passed through a silken sieve. Its odour is acrid and nauseous; when thrown on burning coals it emits that peculiar smell, which generally attends the destruction of animal matter by heat. The chemical history of cantharides is still involved in some obscurity; according to Robiquet, who has furnished us with the most satisfactory analysis, they contain various fatty principles; the phosphates of lime, and magnesia; and the acetic and uric acids; together with a peculiar crystalline principle, in which the vesicatory properties wholly reside, and to which the name of cantharidin has been given by Dr. Thomson.^[338] It may be obtained in plates, having a micaceous lustre; when perfectly pure it is insoluble in water, but it is rendered soluble in that fluid, by the presence of a yellow matter which exists in native combination with it; it is very soluble in oils.

Symptoms of poisoning by Cantharides.

As this substance forms an article of the materia medica it may become an accidental source of poisoning; whilst a general belief in its aphrodisiac powers may induce a trial of its efficacy, to goad the exertions of exhausted nature, or to incense the passion of females, whose seduction is meditated. In the annals of crime in this country, we are acquainted with but few instances in which cantharides have been given with the view of destroying life; we have already referred^[339] to the case of Vaux, who was executed for poisoning with cantharides; there is also that of Sir Thomas Overbury, who, on the confession of the person who gave it to him, is said to have taken it, mixed with his sauces. Cantharides may be administered in the form of powder, infusion, or tincture. The following may be considered the more prominent symptoms which will follow the ingestion of a large dose. Violent retching; copious alvine evacuations, frequently bloody; very severe colics; active inflammation of the stomach and intestines; sometimes universal convulsions, attended with a horror of liquids, resembling that which occurs in hydrophobia; furious delirium, &c. But the affections of the urinary passages, and organs of generation, may be regarded, ?ate?????, as the peculiar symptoms of poisoning by cantharides; such as heat in the bladder, bloody micturition; horrible strangury; painful and obstinate priapism; satyriasis, &c. If the dose has not been sufficient to occasion speedy death, it may produce marasmus.

Organic lesions discovered on dissection.

Where the poison has been administered internally, we shall find the stomach and intestines presenting an appearance of inflammation, very similar to that which we have described as the general result of corrosive poisons. Marks of inflammatory action, and sometimes ulceration, will be also discovered in the urinary and genital organs; especially in those cases where the person dies shortly after the ingestion of the poison.

Methods of detecting the presence of Cantharides.

Where the poison has been administered in substance, we shall generally discover some of its particles mixed with the ejected matter; or, after death, adhering to the coats of the stomach, or to the folds of the intestines, and which may be easily identified by their peculiar green and brilliant hue. If the poison should have been administered in the form of infusion, or tincture, our chemical resources will fail us, and we must rely alone upon the evidence furnished by the symptoms, and organic lesions.

This singular substance was accidentally discovered by Brandt, a chemist of Hamburgh, in the year 1669,^[340] as he was attempting to extract from human urine a liquid capable of converting silver into gold. It was also subsequently discovered by Kunkel and by Boyle, without these latter chemists having, in any way, participated in the researches of each other.

Phosphorus, when pure, is semi-transparent and of a yellowish colour; but when kept some time in water, it becomes opaque externally, and then has a great resemblance to white wax. Its consistence is nearly that of wax; it may be cut with a knife. Its mean specific gravity is 1·770. It generally occurs in sticks. When exposed to the air, provided the temperature be not lower than 43°, it emits a white smoke, which has the smell of garlic, and is luminous in the dark. This smoke is more abundant, the higher the temperature is, and is occasioned by the gradual combustion of the phosphorus. When heated to 148° it takes fire, and burns with a very bright flame, and gives out a great quantity of white smoke, which is phosphoric acid. Oils dissolve phosphorus, provided the temperature be a little raised. Water has no effect upon it, unless it be aerated, when it renders the surface of the phosphorus opaque and white, which in a short time becomes red. This change depends upon oxidation.

Symptoms of poisoning by Phosphorus.

This substance, whether introduced into the stomach in its pure form, or dissolved in oil, will occasion the most violent symptoms, from its escharotic action,^[341] It has been employed in medicine,^[342] in a state of minute division, in the dose of one-fourth of a grain, and is said by Leroi to be very efficacious in restoring and establishing the force^[343] of young persons exhausted by sensual indulgence, and of even prolonging the life of the aged.^[344] It has also been given as a stimulant in local fevers. We are, however, greatly inclined to question the safety of such a practice, notwithstanding the diminutiveness of the dose. The reader will find some interesting cases of poisoning by phosphorus, translated from the German work of Weickard, in Hooper’s Medical Dictionary, under the consideration of that article. Should such a case present itself for the investigation of the forensic physician, he will not find any difficulty in identifying the substance; its external character, its smell, and, above all, its peculiar property of yielding luminous vapour, are too palpable and distinctive, to admit the possibility of error.

Mechanical Poisons—Powdered glass—Enamel powder—Chopped hair, &c. &c.

We have already examined the pretensions of these bodies to the rank of corrosive poisons, (page 145) and we should have not reverted to the subject, but from a wish to introduce the account of “a case of Schirrus in the intestines, arising from hairs remaining in the canal,” as related in the Edinburgh Medical Journal,^[345] by Dr. Burrell, and which had, on the former occasion, escaped our notice. The subject of this history, Laurence Harding, Æt. 35, being a private soldier, was admitted into the regimental hospital, for an unrelenting constipation of the bowels; but it appears also that he had been affected with dyspeptic symptoms, and pain in his abdomen, for several years; which pain was aggravated by the ingestion of solid food. He received but little benefit from the remedies that were administered, his strength gradually declined, and, about a month after his admission, he expired.

“On laying open the abdomen, the stomach was found much thickened throughout its whole substance, and the pylorus very much contracted, which contraction continued down the duodenum. Through all the intestines this thickening and gristly appearance was observed. The colon was prodigiously enlarged in its calibre, until where it forms its sigmoid flexure; at which point there were three distinct holes ulcerated through the coats of the intestine, and forming a communication with the abdominal cavity. Beyond the sigmoid flexure the intestine was contracted in its diameter, so as hardly to admit the little finger to pass downwards. On cutting open the pylorus and small intestines, the internal coats were found to be covered with a soft substance, which resembled size. The internal coats of the colon were of a dark colour, and in general were completely ulcerated, and hanging in shreds. The colour of the colon was of a dark lurid red. At the sigmoid flexure there was much contraction, and the thickening was so great on one side, and the valve found so considerable, as hardly to admit a common bougie through it. The portion forming the sigmoid flexure was cut out; and on laying it open, and removing some hardened fÆces, five or six hog’s brittles were seen distinctly crossing each other in different directions; they were partially invested in the villous coat, which had grown over them, and which had retained them in the different positions in which they were placed; and so firmly were they kept down by those partial coverings, that it required some force to draw them out. The mesenteric glands were of a cartilaginous appearance; the liver was suffused with blood, and the gall-bladder full of bile. The spleen was very small, and compressed into an oblong shape, probably arising from the pressure of the colon when distended with feculent matter.

This man had formerly been a shoemaker. There was no evidence as to the period at which he swallowed these hairs; but, from the derangement which always existed in the bowels, and the pain referred to the sigmoid flexure, little doubt can be entertained but that these hairs were the cause of all his complaints, and ultimately of his death.”

CL. II. ASTRINGENT POISONS.

Lead.

This metal appears to have been known in the earliest ages; and is mentioned several times by Moses.^[346] It has a bluish-white colour; is very brilliant when first cut with a knife, but soon tarnishes by exposure to air; when rubbed violently, it emits a peculiar smell; it is malleable and ductile, but possesses very little tenacity. It is scarcely sonorous; being the softest of all the metals, it yields readily to the hammer. Its specific gravity is 11·35; it melts at 612°. According to the experiments of Dr. Thomson,^[347] it is susceptible of four degrees of oxidation, presenting us with four distinct, and well defined oxides, viz.

Yellow	(protoxide)	contains of lead	91·5	oxygen	8·5
Yellow	(deutoxide)	contains of lead	90·5	oxygen	9·5
Red	(tritoxide)	contains of lead	88·	oxygen	12·
Brown	(peroxide)	contains of lead	80·	oxygen	20·

Lead, in its metallic state, does not exert any action on the living system; but, when oxidized, or in the state of salt, its virulence is very considerable, producing a train of symptoms, so peculiar to itself, as to justify our placing its preparations in a separate class, under the title of astringent poisons, as explained at page 202.

Metallic lead, although per se inert, may occasion deleterious effects when introduced into the stomach, in consequence of its meeting with acids in the primÆ viÆ; from the same cause, liquids which are liable to become in any degree acidulous, if kept in leaden vessels, may be productive of much danger to those who drink them. Pure water, provided the air be excluded, does not appear to exert any sensible action upon this metal; but the combined influence of these agents converts the lead into a carbonate: a fact which is at once exemplified by the white line which is so constantly visible at the surface of the water preserved in leaden vessels. So well acquainted were the ancients with this fact, that we find frequent allusions in their works to the dangerous property of leaden utensils. Vitruvius^[348] published a very strong remonstrance against leaden pipes, when used for the purpose of conveying water; and Galen cautions us continually, not to employ water that has flowed through pipes of this metal; since he had observed that the sediment of such water, (?p?sta?? t?? t?????t?? ?dat??) rendered such as swallowed it, d?se?te??????, subject to disorders in the intestines.

Dr. Lambe, to whom we are indebted for an important work^[349] upon this subject, states, that there is a great diversity in the corrosive powers of different waters; in some places the use of leaden pumps has been in part discontinued, from the expense entailed upon the proprietors by the perpetual want of repair;^[350] and if any acidity be communicated to the water, from the accidental intrusion of decayed leaves or other vegetable matter, its power of dissolving this metal will be increased to a very dangerous extent. The noted colic of Amsterdam is said by Tronchin, who has written a history of the epidemic, to have been occasioned by leaves falling and putrefying in leaden cisterns, filled with rain water. Van Swieten^[351] has also related an instance of a whole family who were afflicted with colic from a similar cause; and Dr. Lambe^[352] entertains no doubt but that the very striking case recorded in the Medical Commentaries,^[353] proceeded more from some foulness in the cistern than from the solvent power of the water; in this instance, the officers of a packet vessel used water out of a leaden cistern; the men also drank the same water, except that the latter had been kept in wood; the consequence was, that all the officers were seized with colic, while the men remained healthy. Sir George Baker has furnished the following striking illustration of the subject. “The most remarkable case that now occurs to my memory, is that of Lord Ashburnham’s family, in Sussex; to which, spring water was supplied from a considerable distance in leaden pipes. In consequence, his lordship’s servants were every year tormented with colic, and some of them died. An eminent physician of Battle, who corresponded with me on the subject, sent up some gallons of that water, which were analysed by Dr. Higgins, who reported that the water had contained more than the common quantity of carbonic acid; and that he found in it lead in solution, which he attributed to the carbonic acid. In consequence of this representation, Lord Ashburnham substituted wooden for leaden pipes; and from that time his family have experienced no particular complaints in their bowels.”

But the most extensive and dangerous source of poisoning by lead, is the presence of this metal in various wines, and acescent drinks, and meats, and which may arise either from accident or design. A knowledge of the different avenues, through which this poison may gain admittance into the human body, is therefore of great importance to the forensic physician, and we shall accordingly proceed to the investigation of the subject.

That certain wines were occasionally liable to produce endemic colics, is a fact which has been long known; although the disease was universally ascribed to a mistaken origin, until the publication of the elaborate researches^[354] of Sir George Baker, into the cause of the Devonshire colic; which, like the same disease observed in other countries, was attributed to the acidity of the liquor so abundantly drunk^[355] in these districts. This celebrated physician, however, was early led to entertain doubts with respect to the truth of this doctrine: “when I consider,” says he, “that this colic of Devonshire is precisely the same disease as that which is the specific effect of all saturnine preparations, and that there is not the least analogy between the juice of apples and the poison of lead, it seems to me very improbable that two causes, bearing so little relation to one another, should make such similar impressions on the human body.” The investigation of the subject completely established the justness of these views; and no doubt remains, but that the endemic colic, which harrassed the cyder drinkers in Devonshire for some years, was the effect of saturnine impregnation, derived from the lead used in the construction of the apple mills and cyder presses; and in some cases, from the pernicious practice of introducing a leaden weight into the cask, or even racking the cyder into leaden cisterns, where the liquor fretted too much, and was thereby in danger of becoming acetous. Sir G. Baker also states that the custom of boiling the must in vessels capped with lead, affords another source of saturnine impregnation; and he informs us that, a few years ago, this very practice produced the Devonshire colic in the county of Kent. Some cyder, which had been made in a gentleman’s family, being thought too sour, was boiled with honey in a brewing vessel, capped with lead. All, who drank this liquor, were seized with this disease; some more, others less violently; one of the servants died very soon in convulsions: several others were cruelly tortured a long time. The master of the family, notwithstanding all the assistance which art could give him, never recovered his health; but died miserably, after having for nearly three years languished under a tedious and incurable malady. Dr. Lambe observes, that the saturnine colic is not endemial in Devonshire, or the other cyder countries, during the whole year, but is confined to those months when the liquor is still new, crude, and the fermentation incomplete. When the liquor becomes fine, the noxious matter in a great measure separates, and is carried to the bottom of the vessel, as the feculencies subside. Tartar is generated during the vinous fermentation, the acid of which, uniting with the lead, forms a salt, scarcely, if at all, soluble in water; and hence the purification which the liquor receives. But although this new salt is insoluble in water, it is otherwise in regard to vinegar; for this acid dissolves a small quantity, and forms a triple compound, an aceto-tartrate of lead;^[356] and since no cyder, or perhaps wine, is wholly destitute of vinegar, it necessarily follows that if the liquor has been once contaminated during the first stages of fermentation, it is impossible for it ever to become entirely pure, except by processes which would render it unfit for drinking.^[357] It has very lately been discovered, that Gallic acid and tannin are capable of combining with lead in solution, and of forming a perfectly insoluble substance, which falls to the bottom of the cask; hence all liquors which have been kept in oak casks, for a certain time, must be freed from lead. This explains a fact with respect to the effect of new rum in the West Indies, of some importance. This spirit, when newly distilled, is found to contain traces of lead, derived from the leaden rims of the coppers, and the leaden worm, used for its condensation; but, by keeping about twelve months in oaken casks, it loses its deleterious properties, and no longer exhibits any traces of this metal.^[358]

Another source, from which acescent liquids may contract saturnine impregnation, is afforded by the metallic glazing of earthenware^[359]; that for instance of the common cream coloured ware is composed of an oxide of lead,^[360] and is accordingly easily acted upon by vinegar, and saline compounds; jars and pots of this description ought therefore never to be used for preserving pickles, jellies of fruits, marmalade, and similar conserves. For the same reason, Sir George Baker protests against the custom of baking fruit tarts in such ware.^[361] Stone ware is glazed with muriate of soda, and is therefore not liable to such an objection.^[362]

The custom which prevails in some parts of England of keeping milk in leaden vessels, is extremely improper; Dr. Darwin^[363] has illustrated this subject by the following case; “A delicate young girl, the daughter of a dairy farmer, who kept his milk in leaden cisterns, used to wipe off the cream from the edges of the lead, and frequently, as she was fond of cream, licked it from her finger. She was seized with the saturnine colic, and semi-paralytic wrists, and sunk from general debility.” We are informed by Mr. Parkes,^[364] that in Lancashire the dairies are furnished with milk-pans made of lead; and that when he expostulated with some individuals on the danger of this practice, he was told that leaden milk pans throw up the cream much better than vessels of any other kind.

There is, says Dr. Darwin, a bad custom in almost all families, and public houses, of washing out their wine bottles by putting a handful of shot corns into them, and by shaking them about forcibly to detach the super-tartrate of potass from their sides; that such a practice may occasionally give origin to serious consequences, will become evident by the relation of the following case.^[365] “A gentleman who had never in his life experienced a day’s illness, and who was constantly in the habit of drinking half a bottle of Madeira after his dinner, was taken ill three hours after dinner with a serious pain in the stomach and violent colic, which gradually yielded within twelve hours to the remedies prescribed by his medical attendant. The day following he drank the remainder of the same bottle of wine which was left the preceding day, and within two hours afterwards he was again seized with the most violent pains, head-ache, shiverings, and great pain over the whole body. His apothecary becoming suspicious that the wine he had drunk might be the cause of the disease, ordered the bottle, from which it had been decanted, to be brought to him, with a view that he might examine the dregs, if any were left. The bottle happening to slip out of the hand of the servant, disclosed a row of shot, wedged forcibly into the angular bent-up circumference of it. On examining the beads of shot, they crumbled into dust, the outer crust (defended by a coat of black lead with which the shot is glazed) being alone left unacted on, whilst the remainder of the metal was dissolved. The wine, therefore, had become contaminated with lead, and perhaps arsenic, for in order to form shot the former metal is alloyed with the latter.”^[366]

But we have, hitherto, only directed the reader’s attention to the different sources from which wine, and acescent liquors, may accidentally derive saturnine impregnation. We have now to state that such liquors have, in different ages and countries, been fraudulently adulterated with lead. It appears to have been early discovered, that wines which have become morbidly acescent may be corrected by the addition of lead; whence, in those countries where Rhenish, Moselle, and other similar wines are drunk, the saturnine colic has been endemic. The celebrated colic which raged in the province of Poitou, towards the end of the sixteenth, and in the beginning of the seventeenth century, was evidently the effect of such adulteration.^[367] We find that, in the year 1487, there was a Recessus Imperii promulgated at Rotenberg; and, in the year 1498, at Friberg; which was enacted, in the year 1500, at Tubingen; and, in the year 1508, at Frankfort; and, in the year 1577, in the same place. By which decrees it was made a capital crime to adulterate wines with litharge, or to use bismuth in the fumigation of them; it having been, at several periods, represented to the Emperors, that great mischief had accrued from such adulterations; and that they had been the cause of insuperable and mortal diseases. It should seem, that these laws were not carried into strict execution; and, indeed, that in the latter end of the seventeenth century, it was hardly known in Germany that such laws existed. In consequence of which, an epidemic colic arose, which was at length traced to the effects of lead in the wines.^[368] A representation of this fact having been made to the Duke of Wirtemberg, it was ordained a capital crime to mix litharge with wine, or even to sell it in the shops, by a decree, bearing date March 10, 1696. But, notwithstanding the severity of this law, we are informed by Zeller, that in the year 1705, the same dangerous experiments were repeated in the circle of Zwaabe, with a view to correct the acidity of the weaker wines. Bishop Watson^[369] informs us that, in the year 1750, the Farmers general in France being astonished at the great quantities de vin gatÉ which were brought into Paris, in order to be made into vinegar, redoubled their researches to find out the cause of the great increase in that article; for nearly thirty thousand hogsheads had been annually brought in for a few years preceding the year 1750, whereas the quantity annually brought in forty years before, did not exceed 1200 hogsheads. They discovered that several wine merchants, assuming the name of vinegar merchants, bought these sour wines, and afterwards, by means of litharge, rendered them potable, and sold them as genuine wines.^[370] Dr. Warren^[371] has related the cases of thirty-two persons in the Duke of Newcastle’s family, who were residing in Hanover in June, 1752, and were seized with the Colica Pictonum, after having used, as their common drink, a small white wine that has been adulterated with lead. Nor has the English vintner been less regardless of the health of his employer. In a popular work on wine making by Graham,^[372] which has gone through six editions, and may therefore be supposed to have done some mischief, we find under the article of vintner’s secrets, the following receipts.—

“Put a pound of melted lead, in fair water, into a cask, pretty warm, and stop it close.”

“Put in a little vinegar, wherein litharge has been well steeped, and boil some honey to draw out the wax. Strain it through a cloth, and put a quart of it into a tierce: and this will mend it, in summer especially.”

We have already alluded to the presence of lead^[373] in the new rum of the West Indies, as the cause of the disease known in that country by the name of the dry belly-ache; it remains for us to state that the excise officers frequently avail themselves of the peculiar power of the sub-acetate of lead to precipitate colouring matter, in order to remove from seized Holland gin, the colour which it obtains by being long kept in the tubs in which it is smuggled over. A practice which it is said renders the gin liable to gripe.

According to the important experiments of Proust,^[374] it appears, that if lead be associated with tin, it will be incapable of furnishing to acids any saturnine impregnation. The following are the interesting conclusions at which this philosopher has arrived, viz.

“That the tinning, which contains even so large a proportion as an equal part of lead, cannot be dangerous; since it is sufficient that the lead should be combined with tin, in order to prevent it from being dissolved, either in lemon juice, or vinegar, the two acids most to be feared. The tin, being more oxidable than the lead, dissolves exclusively in these acids, and prevents the second from being attacked. The lead cannot appropriate to itself an atom of oxygen, but the tin would carry it off in an instant.”

Sugar of Lead—Saccharum Saturni—Cerussa Acetata—Plumbi Super-acetas.

This salt of lead, to whose presence the numerous accidental maladies above enumerated are to be chiefly attributed, occurs in commerce in the form of irregular masses resembling lumps of sugar, being an aggregation of acicular four-sided prisms terminated by dihedral summits; its taste is sweet and astringent. It is soluble in 25 parts of water, hot, or cold; when common spring water, however, is employed for such a purpose, a white precipitate occurs from the presence of a certain proportion of sulphates and carbonates.

When this salt is exposed to the action of heat, it undergoes aqueous fusion, then dries, and at length is decomposed, leaving a globule of metallic lead, mixed with the yellow protoxide, and an acid product of a fetid smell. This decomposition is similar to that which vegetable substances undergo when heated for some time. The quantity of metallic lead, thus obtained, will be more considerable if the salt has been previously mixed with charcoal, and particularly if it be submitted for a long time to the action of a powerful heat. The strong sulphuric acid of commerce, when poured upon sugar of lead in powder, decomposes it with effervescence, and disengages vapours of acetic acid.

This must be considered as an active preparation, and may, when administered in doses of a few drachms, speedily occasion death. At the same time, like other poisons, it may by judicious administration, become a valuable remedy. See Pharmacologia, art. Plumbi Super-acetas.

In consequence of the sweet taste of this salt, children have been induced to swallow it.

Goulard’s Extract. Liquor Plumbi Sub-acetatis.

This liquor is a saturated solution of the sub-acetate of lead. Spring water, from the salts which it contains, produces with it a very milky and turbid appearance; and even when distilled, in consequence of the carbonic acid diffused through it, it will occasion precipitation. It is principally used as an external application to diminish inflammation, an effect which it probably produces by paralysing the nerves of the part. Cases have occurred where this lotion has been accidentally swallowed, and the usual symptoms of saturnine poisoning have supervened. How far its external application may be capable of occasioning mischief, will form a subject of inquiry under the consideration of the physiological action of the preparations of lead.

White Lead. Sub-Carbonate of Lead. Cerusse.

The substance, known in commercial language by the name of White Lead, has received at different times, very various appellations, in consequence of the fluctuating opinions which have prevailed respecting its composition. Thus it has been successively styled a sub-acetate, an oxide, and a sub-carbonate; of which the last is unquestionably the correct name. In the large way it is prepared by exposing sheets of metallic lead to the fumes of vinegar. The sub-carbonate so produced appears as a white, brittle, and scaly substance, on the surface of the lead; which is scraped off, and afterwards ground in mills fitted for the purpose. Formerly, it was ground dry, and the workmen suffered severely from the operation; it is now ground in water, and the sub-carbonate is afterwards dried in earthen pans placed in stoves, heated by means of flues; still, however, persons employed in grinding white lead, as well as painters^[375] who are constantly using it, occasionally suffer severely, from the want of cleanliness in not washing their hands before eating, by which some of the white lead is introduced into the stomach with their food.

Litharge. Semi-vitrified Oxide of Lead.

This is a yellow protoxide of lead, which has been melted, and left to crystallize by cooling. It is in the form of small reddish, or yellowish scales, which are brilliant and vitrified. Its character is so peculiar that it cannot easily be mistaken. It is employed for various purposes in the arts, and is the saturnine preparation more usually selected for the purpose of removing acidity from wines, as above related.

When treated with a muriatic salt, and submitted to a high temperature, a muriate of lead is produced, of a bright yellow colour, the brilliancy of which may be much heightened by grinding it as usual with oil. In this state it forms the pigment known by the name of Turner’s yellow, or patent yellow.^[376] It is very poisonous.

Red Lead. Minium.

This red oxide of lead is easily distinguished by its colour, weight, and the facility with which it yields metallic lead, when heated with carbonaceous matter. Common red wafers, which derive their colour from this oxide, afford a striking illustration of this fact, for if burnt in a candle, globules of metallic lead will be observed to flow from them. It is poisonous; and we have already alluded to a case where Gloucester cheese^[377] occasioned deleterious effects, in consequence of its adulteration with red lead. (p. 277) It is destructive also to inferior animals, apparently in very small quantities; red wafers prove poisonous to birds who may pick them up; and the same paste is sold for the purpose of destroying beetles, in which it succeeds very effectually. Since it is employed as a pigment, it may on many occasions prove an accidental cause of poisoning; there is indeed one very common and dangerous source, mentioned by Sir George Baker,^[378] which deserves to be particularized in this place, viz. the practice of painting toys with red lead, and other poisonous substances; children, observes this distinguished physician, are apt to carry every object which gives them delight to their mouths, the painting of toys, therefore, with poisonous colours, is a practice which ought to be abolished, and is the more open to censure, as it is of no real utility.

Symptoms of poisoning by the different preparations of Lead.

The effects of this poison will vary considerably according to the quantity swallowed, and the circumstances under which it is taken. We shall, therefore, first consider its operation, in doses sufficiently large to occasion at once violent effects; and then describe its agency as an accumulative poison, where it is introduced into the system gradually, and in small quantities, so as to act slowly and imperceptibly, and to lay the foundation of irreparable mischief, before any alarm is occasioned.

1. Symptoms which follow a large dose. Where a salt of lead has been taken in a considerable dose, the patient soon experiences excruciating pains in the abdomen, accompanied with sickness and vomiting; the colic increases to a violent degree, but admits of temporary alleviation by pressure, a circumstance which at once distinguishes it from the effects of corrosive poison. Although it is necessary to observe, that inflammatory symptoms may afterwards occur, where the dose has been very considerable, and the consequences direct and speedy.

The patient describes the pain as if produced by a boring instrument, and the abdominal muscles become knotted, and sometimes painfully retracted with all the contents of the abdomen towards the spine.^[379] The sphincter muscles of the bladder and anus are always affected; sometimes strangury and tenesmus are the consequences; at other times, a total incapacity of making any water at all, and so great a contraction of the sphincter ani that a clyster can hardly be introduced. After suffering these torments for a period of an indefinite duration, delirium and cold sweats may supervene, and the patient die in convulsions. If, however, the treatment has been prompt and judicious, and the quantity of poison has not been excessive, he may recover from its immediate effects, and live to testify the severity of the consecutive phenomena. A most inveterate constipation of the bowels will continue for a considerable period, and there will be an occasional recurrence of colic; at length a peculiar species of palsy will supervene in the upper extremities, especially affecting the muscles of the fore arm, and wrist,^[380] Citois has given us a striking description of this stage of the saturnine disease. “Per vicos, veluti larvÆ, aut arte progredientes statuÆ, pallidi, squalidi, macilenti conspiciuntur, manibus incurvis et suo pondere pendulis, nec nisi arte ad os et cÆteras supernas partes sublatis, ac pedibus non suis, sed crurum muculis, ad ridiculum, ni miserandum, incessum compositis, voce clangosa et strepera.” It does not appear that the train of symptoms above described has ever been excited by any other external cause than the one here assigned. Whenever we meet with colic, attended with paralytic symptoms of the extremities, we may at once conclude that it has arisen from the influence of lead.

The disease has been described by authors under the name of the colic of Poitou,^[381] or colica Pictonum,^[382] from the circumstance of its having raged with such epidemic fury in that province, in consequence of the adulteration of its wines with lead. It is also mentioned as the painter’s colic, since this class of artists is very commonly visited by the disease, in consequence of the white lead contained in their pigments. At the Lead Hills, it is known to the miners, under the provincial name of milreek; and in Derbyshire, under that of belland.^[383]

2. Symptoms arising from the introduction of lead into the system, by small and repeated doses.

The effects produced upon various artists by the imperceptible operation of lead, sufficiently shew the power which this metal possesses of accumulating in the human system, and it is probable, says Sir George Baker, that from an observation of such slow, but certain effects of lead, the French and Italians derived the hint of preparing their celebrated poisons, called “Poudres de Succession;”^[384] the basis of which has been supposed to have been some preparation of that mineral. Zeller mentions a certain chemical operator, near the confines of Bohemia, who, after having diligently applied himself to the composition of poisons, did, by means of lead, combined with some more volatile and corrosive substance, prepare a most slow poison, which given to dogs and other animals, had the power of destroying them, without producing any violent symptoms, after several weeks, or even months.^[385]

The following-curious case,^[386] communicated by Dr. Wall, of Worcester to Sir George Baker, will serve to illustrate the present subject, and to shew that lead may gain admittance into the human body, unobserved, and even unsuspected. “A gentleman of Worcester was the father of a numerous offspring, having had one and twenty children, of whom eight died young, and thirteen survived their parents. During their infancy, and indeed until they had quitted the place of their usual residence, they were all remarkably unhealthy; being particularly subject to disorders of the stomach and bowels. The father, during many years, was paralytic; the mother, for as long a time, subject to colics and bilious obstructions. She died at last of an obstinate jaundice. This disease had been several times removed by the use of the Bath water; but it always came on again soon after her return to Worcester; and at last eluded every method and medicine which was tried. After the death of these parents, the family sold the house which they had so long inhabited. The purchaser found it necessary to repair the pump. This was made of lead; and, upon examination, was found to be so corroded, that several perforations were observed in the cylinder, in which the bucket plays; and the cistern in the upper part was reduced to the thinness of common brown paper, and was full of holes like a sieve. The waters of this town are remarkably hard. It is then more than probable that the water of this pump, thus impregnated with lead, occasioned the unhealthiness of the family who drank it. I have been just informed by the plumber,” adds Dr. Wall, “that he had several times repaired the pump in question; and that he had done so not more than three or four years before the gentleman’s death; when he found it nearly in the same state as it has been described; so that the corrosion was effected in a short time; and consequently the water must have been very strongly impregnated with the noxious quality of the metal.”

Organic lesions discovered on dissection.

The reports of the dissection of those who have been destroyed by saturnine poisons are far from being satisfactory. Where the person has died from the primary effects of a large dose of the acetate of lead, the stomach has betrayed a state of inflammation, similar to that which results from the action of a corrosive poison; black points and spots, from venous extravasation, have been also observed in the interior of this viscus; M. Orfila states that he has seen in the stomach of animals who have taken a large dose of the acetate of lead, and have not vomited, a membraneous lining tolerably thick, of an ash colour, easily detaching in small pieces; the origin of which appeared to be owing to the decomposition of a part of the acetate of lead by the mucous, bilious, and other fluids, contained in this viscus. The mucous membrane lying under this lining, was of a dark grey colour throughout its whole thickness, and appeared to have exercised the same action on the acetate of lead. The case is very different in those who have died from the slow action of this metal; all anatomists agree in reporting, that in the colica pictonum, the digestive canal exhibits no vestige of inflammation;^[387] but the diameter of the large intestines, especially that of the colon, is generally contracted; thus displaying the effects of that operation, which is supposed to be characteristic of the compounds of lead, and which has bestowed upon them the peculiar designation of astringent poisons. FoderÉ states that the mesentery and its glands; and the lacteal and lymphatic vessels, are inflamed and obstructed, and the thoracic duct almost obliterated; the liver, spleen, pancreas, and lungs often inflamed, tumefied and purulent, and even the heart shrivelled;^[388] and the whole body, in consequence of the constriction of the chyliferous vessels, in a state of complete marasmus. Upon this passage Orfila makes the following observation. “We are under the necessity of declaring, that almost all these signs are wanting in the majority of the cases of simple colic of lead, terminated by death.” Fourcroy, in a note to his translation of Ramazzini, “De Morbis Artificum,” observes that the intestines have, in these cases, been discovered distended by air, parched, and slightly altered in colour; and that in the larger ones, balls of dry, dark coloured, excrementitious matter, have been found.

Physiological action of Lead Poisons.

The preparations of lead seem to act upon the nervous system, destroying its energy, and thereby producing paralysis. Whether this is effected through the medium of the circulation, or whether they produce their effects without being absorbed, appears to us to be a question which has not hitherto received a satisfactory answer. It must, however, be admitted that they act upon the alimentary canal, by coming into contact with its nerves; and in some cases, where the dose of the acetate has been large, it may have produced death by the local injury which it inflicted. Dr. Lambe observes upon this subject, that “certain facts render it probable that lead does not operate entirely through the medium of the circulation, nor by nervous sympathy; but also topically, affecting the part to which it is applied more than the other parts of the body.” This latter position is clearly established by the beneficial effects occasioned by the topical application of lead to inflamed surfaces; nor can any doubt exist as to the fact of such applications having produced local paralysis. There is a paper in the third volume of the Medical Transactions by Dr. Reynolds, in which the case of a gentleman is detailed, who brought on a temporary paralysis of the sphincter ani, by freely using Goulard’s lotion for the cure of piles. Foreign writers have also maintained that saturnine applications have frequently occasioned impotence; for further information upon this subject the reader may refer to Istitutione di Medicina Forens: di Tortosa, vol. 1, p. 58; also Fritze Compend: sopra i Malat. Vener. p. 189; and Monteggia Annotat. sopra i Mali Venerei, p. 36. Sir George Baker states that he has some reason to doubt, whether litharge, the common basis of our plasters, when used for the purpose of dressing issues, has not, in certain irritable constitutions, produced some of the ordinary effects of saturnine preparations taken internally. There have been instances of children thrown into convulsions, by cerusse, sprinkled on excoriated parts. Zeller quotes, on the authority of Molingius, a remarkable instance of the pernicious effects of litharge, externally applied.^[389] Sir George Baker met with a most violent and obstinate colic, which seemed to have been occasioned by some litharge, mixed in a cataplasm, and applied to the vagina, with a view to allay a troublesome itching; and he says that he was informed by Dr. Petit that Goulard’s poultice applied for some time to a patient’s knee, in St. George’s hospital, occasioned violent pain in the bowels, which did not cease until the poultice had been removed; nor are authorities deficient to prove, that the fashionable application of cerusse to the skin has been followed by obstinate colics, pains, and tremors. We have been desirous of laying before our readers the above authorities, in proof of the constitutional effects which may be occasionally produced by the external application of lead, since the fact has been questioned, and is still considered by many as involved in doubt and uncertainty. Dr. Lambe is inclined to believe, that “to the production of the saturnine colic, it is necessary that the metal should be applied immediately to the stomach and intestines.” If this hypothesis be just, he excludes nervous sympathy, as well as absorption, as a proximate cause of saturnine colic; and, consequently, no dependence can be placed on the accounts given by the above pathologists with regard to the production of such an effect by lotions and cataplasms of lead.

Of the chemical processes, by which the presence of lead may be detected.

These will necessarily vary according to the different states of combination in which it may be supposed to exist; we shall, therefore, proceed to consider the modes of establishing its presence, 1, In solution in water; wine; spirit; and oils. 2. In a state of mixture with various solids. 3. Combined with solid or liquid aliments.

1. The lead exists in some unknown state of combination in solution in water. We are greatly indebted to Dr. Lambe^[390] for the able directions which he has afforded us for ascertaining the presence of minute portions of lead in water; and we recommend the practitioner, who may be engaged in such an investigation, to peruse his work with attention. The following are the reagents through which our analysis must be conducted.

(a) Sulphuretted hydrogen. A solution of this gas in distilled water is a very delicate test for lead, throwing down a precipitate of a very dark brown colour, approaching to black. The competency, however, of this test to the discovery of very minute quantities of lead, in certain states of combination, has been questioned by Dr. Lambe; who was enabled to detect the presence of this metal, by other methods, in water that manifested no indication with sulphuretted hydrogen. He detected it, for instance, in the precipitate occasioned in such water by the carbonate of potass or soda. In operating on these waters, he noticed the following appearances.

1. The precipitate, produced as above stated, when re-dissolved in nitric acid, formed a dark cloud with sulphuretted hydrogen.

2. Although the sulphuretted hydrogen formed no cloud, the precipitate itself became darkened by it.

3. The precipitate re-dissolved in nitric acid, (as in 1) formed, with sulphuretted hydrogen, a white cloud.

4. Sulphuretted hydrogen neither formed a cloud, nor darkened the precipitate.

5. In the cases 2, 3, 4, if the precipitate be heated to redness, in contact with an alkaline carbonate; and after dissolving out the carbonate, it be redissolved in nitric acid; then sulphuretted hydrogen will form a dark cloud with the solution. In these experiments it is necessary that the acid used to redissolve the precipitate be not in excess; if it should so happen, the excess must be saturated, before the test is applied. It is better to use so little, that some precipitate may remain undissolved. The nitric acid, used in these experiments, should be perfectly pure; and the sulphuretted hydrogen test should be recently prepared by saturating distilled water with the gas.

(b) Sulphate of soda, or potass. This test will produce a white precipitate in water, containing one hundred-thousandth of its weight of lead; and is considered by Dr. Thomson as the most unequivocal reagent of that metal which we possess. “The precipitate is a fine dense powder, which speedily falls to the bottom, and is not re-dissolved by nitric acid; no other precipitate can be confounded with it, except sulphate of baryta, and there is no chance of the presence of baryta in solution in water.”^[391]

(c) Muriate of soda. One of the methods of analysis proposed by Dr. Lambe, consists in precipitating the lead by common salt; but as the muriate of lead is partly soluble in water, this test cannot be applied to small portions of suspected water. The precipitate must, therefore, be collected from two or three gallons, and heated to redness with twice its weight of carbonate of soda. The alkaline carbonate is then to be dissolved out, and nitric acid added, in order to saturate any superfluity; the sulphuretted hydrogen test will then produce its indication.

(d) Reduction of the metal. This is undoubtedly the most satisfactory of all the tests; and, except the trouble of collecting a large quantity of precipitate, is not embarrassed with any difficulty. The precipitate may be mixed with its own weight of alkaline carbonate, and exposed either with, or without, the addition of a small proportion of charcoal, to a heat sufficient to melt the alkali. On breaking the crucible, a small globule of lead will be found reduced at the bottom. The precipitate from about fifty gallons of water yielded Dr. Lambe about two grains of lead.

2. The lead is dissolved in wine. For the detection of this dangerous fraud, the reagent invented by Dr. Hahnemann affords a ready and convenient test. It consists of water saturated with sulphuretted hydrogen gas, and acidulated with muriatic acid;^[392] this latter ingredient is added for the purpose of preventing the precipitation of any iron, which the wine might accidentally contain. This liquor will, if added in the proportion of one part to two of wine, produce with the smallest quantity of lead, a dark coloured, or black precipitate; which, if collected, dried, and fused before the blow-pipe on a piece of charcoal, will yield a globule of metallic lead. Or we may modify the experiment by passing a current of sulphuretted hydrogen gas through the wine, having previously acidulated it with muriatic acid, to prevent the precipitation of the iron.

A farther proof of the presence of lead in wines is the occurrence of a precipitate, on adding a solution of the sulphate of soda.

The most satisfactory proof, however, is derived by distilling off the alcohol, and calcining the residuum with charcoal, in order to obtain the metallic lead.

The quantity of lead which has been detected in sophisticated wine, may be estimated at forty grains of the metal in every fifty gallons,^[393] but this will of course be liable to vary with the degree of acidity it was intended to correct.

3. The lead is dissolved in oils. In this case the lead may be detected by shaking, in a stopped phial, one part of the suspected oil, with two or three parts of water, impregnated with sulphuretted hydrogen. This test will announce the presence of the deleterious metal, by occasioning a dark brown, or black colour.

4. The lead is mixed with alimentary matter. M. Orfila has furnished us with the following directions for assaying the matter vomited, or that which may be found in the digestive canal, after death. “After having expressed the fluid portion through a piece of fine linen, it must be assayed by the tests, which have been already enumerated as being capable of detecting the salts of lead; and if the precipitates obtained are of a nature to induce a belief, that the fluid contains some preparation of this kind, it must be evaporated to dryness, and calcined with charcoal in a crucible; when, at the expiration of three quarters of an hour, metallic lead will be obtained. If all the experiments made on the fluid portion of the matter vomited, for the discovery of this poison, should be fruitless, the whole of the solid portions, previously dried, should then be calcined with potass and charcoal, by which means metallic lead will be obtained.”

The poisons of which we are about to offer the physiological and chemical history, although more numerous than those which belong to the mineral kingdom, are, notwithstanding, of far less importance in a forensic point of view. With the exception of opium, and some few others, they must be considered as objects of accidental, rather than of criminal poisoning; and even with respect to the former narcotic, it may be said to afford more frequently the means of destruction to the suicide, than to the assassin.

The sensible qualities of smell, taste, and sometimes colour, which so eminently characterise deleterious plants, must necessarily render them ill calculated to favour that secresy, which constitutes the indispensable companion of crime; while their bulk, and the pharmaceutical preparation which they require, are alike inconsistent with the hope of concealment.

Thus we receive, as it were, from Nature, that protection which art can no longer supply; and the commission of crime is either prevented or discovered, in cases where the powers of chemistry would fail in its detection.

The objects which constitute the vegetable kingdom differ from every species of mineral matter, not only in their peculiar organized structure, but in the chemical arrangement of their elements; those of inorganic matter are generally combined in very simple proportions, as one and one, or one and two, &c. whereas in organized bodies, their proportions are much more complicated; and Dr. Ure observes,^[394] that such substances derive the peculiar delicacy of their chemical equilibrium, and the consequent facility with which it may be subverted and new modelled, to the multitude of atoms grouped together in a compound; hence too, as Mr. Children^[395] has observed, is one reason of our utter inability to reproduce even the simplest body of this class, when once its elements have been separated; it is not in the diversity of these elements, but in the manner in which they are grouped, that this peculiarity consists, for, continues the accomplished chemist last mentioned, “vegetable substances seldom contain, as essential, more than three principles—oxygen, hydrogen, and carbon, and sometimes azote. With four simple elements then, a brief alphabet for so comprehensive a history! has a bountiful Omnipotence composed the beautiful volume of the living world, where, turn to what page we may, fresh loveliness meets the eye, fresh cause of admiration and delight.”

The analysis of vegetable bodies resolves itself into two parts, each of which constitutes an equal object of interest to the forensic physician; who, it will be shewn, may occasionally derive important information from both. The first relates to the discovery of the proximate principles of a vegetable substance. The second, to that of its ultimate elements. By the proximate, or, as they are sometimes termed, the immediate principles, we mean those compound substances which exist in the living plant in a state identical with that, under which chemical processes exhibit them, and are chiefly separable by the action of different solvents. The number of these principles is considerable, as gum, starch, sugar, gluten, extractiue, tannin, oils, acid, &c. &c. By the ultimate elements, we understand those, of which the proximate are composed, as oxygen, hydrogen, carbon, and azote. In submitting a plant to destructive analysis, for the purpose of obtaining its ultimate elements, we shall derive compounds, which formed no part of the vegetable structure, and which result from a new arrangement of the elements composing it; acetic and carbonic acids, for example, are obtained by the destructive distillation of several vegetable substances, in which neither of these acids existed ready formed, but only their elements.^[396] It may easily be imagined to what numerous fallacies such a law of composition must have given origin, in the earlier periods of chemical inquiry; and it is equally evident, that the utmost refinement of chemical science, and the most rigorous methods of analysis, will be required to enable us to deduce any satisfactory conclusion with respect to the quality of a plant, from these data. Such perfection, indeed, has not hitherto been attained, but the period is probably not far distant, when our most sanguine anticipations upon this point may be realised. We have only to trace the history of this branch of chemistry for the last century, to become satisfied of its gradual and important progress towards such an epoch, and of the improvements of which this department of vegetable analysis is farther susceptible; let us, for the sake of illustration, only compare the rude results obtained by the academicians of Paris, at about the commencement of the seventeenth century, with those of MM. Gay-Lussac and Thenard^[397], or with those, very lately instituted in this country by Dr. Ure,^[398] and we shall perceive that while the former of these experimentalists, by the aid of heat, were unable to form the slightest distinction between the most inert, and the most poisonous species of plants, the latter, by means of the same agent, aided by the modern doctrine of equivalent ratios, has succeeded in establishing the proportions in which the elements of each vegetable body combines; and with such accuracy, as to discriminate between substances, which bear the greatest analogy to each other; as between the varieties of sugar, and those of oil; and even between common flax, and the same substance prepared according to the improved process of Mr. Lee. This statement is sufficient to show the capability of ultimate analysis, on certain occasions, to identify vegetable bodies; but we are, at present, scarcely advanced far enough in such an investigation, to make it subservient to the detection of vegetable poisons. Nor has our knowledge with regard to proximate analysis, been less successfully advanced. The late researches of the French and German chemists have demonstrated the existence of several new alkaline bodies in the class of vegetable poisons, to which some of these plants appear to be exclusively indebted for their activity, as the poppy, hellebore, colchicum, &c.; and whose characters are so distinct and striking, as to enable the chemist to recognise their presence by appropriate re-agents. In other cases, the virulence of a plant would appear to depend upon the combination of several^[399] proximate principles; while in some few instances there exist in the same individual vegetable, two distinct elements of activity, as illustrated by the interesting history of tobacco.

In cases of vegetable poisoning it will occasionally occur, that some remains of the plant may be collected; and seeds, portions of the fungi, and leaves, may be found in the contents of the stomach; whence a knowledge of botany becomes indispensable. This branch of science is, moreover, important to the toxicologist, as enabling him to pursue the study of plants with greater precision; for experience has shewn that there is a wonderful analogy between the structure of those plants which resemble each other in medicinal operation. Thus those which, from their dismal and dusky appearance, have been arranged under the title of LuridÆ, are in general highly poisonous; they also possess a very peculiar and disagreeable smell, so that Nature has, upon this occasion, kindly given us notice of approaching danger, by means of our senses.

Of equal importance with the knowledge of the generic and specific characters, is that of their sensible qualities, and the changes which these latter undergo by pharmaceutical preparation.

Most of the subjects of this class constitute articles of Materia Medica; so that ignorance on the one hand, and accident on the other, may render them the unexpected source of mischief. With respect to the physiological action of these bodies, the reader has only to refer to our classification at page 207, to perceive that it will not admit of generalization; for each division, it will be observed, contains individuals which belong to the class of acrid poisons.

As the history of most of these articles is to be found in works on Materia Medica, we shall not enter so fully into their properties, as we might otherwise have considered necessary.

Camboge or Gamboge.

This beautiful gum-resin is obtained by making incisions in the leaves and young sprouts of the Stalagmitis Cambogioides^[400] (Polygamia MonÆcia—Nat. ord. TricoccÆ. Wild:) It is first collected, in the kingdoms of Siam and Ceylon, in cocoa-nut shells, and is thence transferred into large earthen jars, where it remains until it is nearly dried to a cake, when it is formed into rolls, and wrapped up in leaves. It is imported into Europe^[401] in cases and boxes. Its deep yellow colour, which is so materially brightened by being wetted, and its shining fracture, are characters sufficiently striking to enable the practitioner to identify it; and when we add to these the history of its habitudes with different menstrua, the chemist will have no difficulty in detecting its presence, viz. when triturated with water, two-thirds of its substance are speedily dissolved, and a turbid solution results; alcohol dissolves nine-tenths, and forms a yellow transparent tincture, which is rendered turbid by the addition of water; sulphuric ether dissolves six-tenths of the substance; it is also soluble in alkaline solutions, and the resulting compound is not rendered turbid by water, but is instantly decomposed by acids, and the precipitate so produced is of an extremely brilliant yellow colour, and soluble in an excess of acid.

Its action upon the animal oeconomy is that of a powerfully drastic purge. We are, however, not acquainted with any case in which death followed its administration. From the experiments made upon animals, it would appear to produce its effects by a local action on the textures, with which it comes in contact, and it will accordingly be found in the third class of our physiological classification, (page 207.)

White Hellebore.^[402]

Veratrum Album. (Polygamia—MonÆcia—Nat. Ord. CoronariÆ. Linn.—Junci. Juss.)

This is undoubtedly the true hellebore of the ancients. It is a native of the mountainous parts of Greece, Italy, Switzerland, and Russia. Those specimens which are cultivated in our gardens flower in July. The root is the only part employed in medicine, but every part of the plant is extremely acrid and poisonous. Upon the animal oeconomy it acts as a violent cathartic and emetic; producing bloody stools, excessive vomitings, great anxiety, vertigo, tremors, sinking of the pulse, syncope, cold sweats, convulsions, and death. There are many cases on record, where such effects have followed the ingestion of this plant. Helmont reports that a royal prince died in the course of three hours after taking a scruple of this poison, which induced convulsions; and Vicat^[403] relates the case of a tailor, his wife, children, and workmen, who having taken soup, in which, through mistake, the root of white hellebore had been introduced instead of pepper, were seized with a universal coldness, and such extreme debility, as to become nearly insensible. At the expiration of two hours, the eldest child, who was not four years of age, began to vomit copiously, but with considerable straining; the rest were shortly after in the same condition. Vicat, who was called in at this critical period, ordered them to take a considerable quantity of warm water and oil; shortly after which he administered an infusion of mallow sweetened with honey; by which means, we are informed, they were relieved, and ultimately restored. According to the testimony of various physiologists, as well as from the experiments of Orfila, it appears that this plant, if externally applied, will produce the same effects. Etmuller says, that the external application of the root to the abdomen will produce vomiting; and Schroeder observed the same phenomenon to take place in a case where it was used as a suppository; the juice of the plant has been also applied to the purpose of poisoning arrows. It must, therefore, act by being absorbed into the circulating current, thereby destroying the energy of the nervous system. It accordingly finds a place in the second division of our classification. Late experiments upon this substance have shewn that its activity depends upon a peculiar alkaline principle, to which the name of veratria^[404] has been given; and that it exists in native combination with an excess of gallic acid, (super-gallate of veratria).

When taken internally, as a poison, the most effectual antidote is said to be a very strong infusion of nut-galls.

Black Hellebore. Melampodium.

Christmas-rose. (Polyandria Polygynia. Nat. Ord. MultisiliquÆ, Linn. RanunculaceÆ, Juss.)

This plant, which has derived its name from the dark colour of the root, is a native of Austria, the Apennines, and Italy; it has, however, obtained a place in our gardens,^[405] and from the circumstance of its flowering from December till March, it has acquired the name of the christmas rose. The fibres of the roots are the parts employed in medicine; their odour is foetid, and their taste bitter and acrid. Its action upon the animal oeconomy is similar to that of the preceding species. Morgagni relates the history of a person who took half a drachm of black hellebore, and expired eight hours afterwards. M. Orfila states that inflammation of the rectum is a constant occurrence, where the animals who have taken this root, have survived its administration for a few hours.

This plant is a native of England, growing in shady places, on a chalky soil, and flowering in March and April. Like the former species of hellebore, it is capable of producing fatal effects. A case is related in the London Chronicle, 1768, no. 1760, of a child who died in consequence of taking the root of this plant in the pulp of an apple.

Elaterium. Wild, or squirting Cucumber.

Momordica Elaterium (MonÆcia Monadelphia. Nat. Ord. CucurbitaceÆ.)

This plant is a perennial native of the south of Europe, flowering in June and July; it is cultivated in England, but does not survive the severity of our winters. The fruit (poma) has the appearance of a small oval cucumber, of a greyish colour, and covered with prickles. When fully ripe it quits the peduncal, and casts out the seed and juice, with great force, and to a considerable distance, through the hole in the base where the foot-stalk is inserted, whence the name of squirting cucumber. The author has instituted numerous experiments upon this plant, the results of which will be found fully detailed, under its history, in the fifth edition of his Pharmacologia.

The plant appears, from the testimony of Dioscorides, and other writers, to have been employed by the ancient physicians with much confidence and success as a cathartic; all the parts of the plant were considered as purgative, although not in an equal degree; thus Geoffroy, “radicum vis cathartica major est quam foliorum, minor vero quam fructuum.” This question, however, has been very lately set at rest, by the valuable experiments of Dr. Clutterbuck,^[406] which prove that the active principle of this plant resides more particularly in the juice which is lodged in the centre of the fruit. The forensic physician, however, will scarcely be liable to meet with a case of poisoning by the fruit of this plant. It is from that preparation of the juice, which is admitted into our Pharmacopoeia, under the title of Extract of Elaterium, that we may expect to meet with mischief.

This substance subsides spontaneously from the juice of the fruit; and occurs in commerce in little thin cakes, or broken pieces, bearing the impression of the muslin upon which it is dried; its colour is greenish, its taste bitter, and somewhat acrid; and when tolerably pure it is light, pulverulent, and inflammable. Notwithstanding its extreme activity, it does not, according to our experiments,^[407] contain more than a tenth part of active matter, which is a vegetable proximate principle, sui generis, and to which we have given the name of Elatin. By treating the Elaterium with alcohol, this principle may be obtained; it imparts to the spirit a most brilliant, and beautiful grass green colour—but see our experiments upon this subject. The action of elaterium is that of a most violent drastic cathartic, especially affecting the rectum. It destroys life by its local action, and consequently finds a place in the third division of our classification.

This is the fruit of the Cucumis Colocynthis (Monoecia Monodelphia, Nat. Ord. CucurbitaceÆ) an annual of Turkey and Nubia. It is of the size of an orange, of a yellowish-white colour, devoid of smell, round, dry, light, spongy, and smooth on the outside, when ripe; it is trilocular, each cell containing many ovate, compressed, whitish seeds, enveloped by a white spongy pulp. It is imported into this country, after having been peeled, and dried in a stove. Its taste is extremely bitter and acrimonious. It acts upon the human body as a powerfully drastic purgative. Fordyce,^[408] relates the case of a woman who was subject to colics for the space of thirty years, in consequence of having taken an infusion of this fruit in beer. Tulpius^[409] has also furnished us with an account of the tremendous effects produced by an overdose of the same article; and Orfila has shewn, with his usual accuracy, that it acts not only locally upon the primÆ viÆ, but by being absorbed, and carried into the circulation.

Euphorbium. Euphorbia Officinarum (Dodecandria Trigynia. Nat. Ord. TricoccÆ Lin. EuphorbiÆ Juss.)

This gum resin is imported from Barbary, in drops, or irregular tears; its fracture is vitreous; it is inodorous, but yields a very acrid, burning impression on the tongue. Its acrid constituent resides exclusively in that portion which is soluble in alcohol. This poison has been sometimes administered imprudently as a purgative when it has produced vomiting, and bloody stools. Lamotte speaks of a clyster prepared with it, which proved fatal. It acts as a caustic upon the textures with which it comes in contact, and thus destroys life by a local action; indeed its nature is so acrid that when applied to the hair, or to warts, it causes them to fall off. Scopoli mentions the case of a person who, having the eye-lids closed, allowed them to be rubbed with the juice of this plant; in consequence of which inflammation followed, and the sight was lost. In pulverizing the gum-resin, the parmaceutist should take the precaution of previously moistening it with vinegar, or the powder will rise, excoriate his face, and excite violent inflammation of the eyes. There are many species^[410] of Euphorbium, or spurge, which are highly poisonous; and, being indigenous, they have frequently proved the cause of mischief; during the last summer the author was consulted on the occasion of a family of children having been seized with a violent inflammation of the eyes, and eruption on the face, when the phenomenon was very satisfactorily traced to the action of the Euphorbia peplus, which was growing very luxuriantly in the garden where the children had been playing.

Savine.

Juniperus Sabina. (DiÆcia Monadelphia—Nat. Ord. ConiferÆ.)

This shrub is a native of the south of Europe and the Levant; but has been long cultivated in our gardens. The leaves and tops of the plant have a strong, heavy, disagreeable odour, and a bitter, hot taste, with a considerable degree of pungency; qualities which depend upon the presence of an essential oil. Upon the animal system it acts as a very powerful stimulant, and has been received into the list of the materia medica, as an active emmenagogue; while it has long enjoyed, amongst the vulgar, the reputation of being capable of producing abortion.^[411] Upon this point we have only to observe, that it does not exert any specific action on the uterus; but as a violent medicine, acting upon the general system, it might, in common with other stimulants, produce so much disturbance as to be followed by abortion. The experiments of Orfila have shewn that savine exerts a local action, but that its effects depend principally on its absorption, through which medium it acts on the nervous system, the rectum, and the stomach.

Aconite. Monkshood.

Aconitum Napellus (Polyandria Trigynia—Nat. Ord. MultisiliquÆ, Linn. RanunculaceÆ, Juss.)

There are several species of aconite, all of which are poisonous. The monkshood is a well known plant, met with in our gardens, and when swallowed in any quantity will produce the symptoms, characteristic of vegetable poisons. All the parts of aconite, in the fresh state, when chewed, produce a sense of heat, and shortly afterwards a sensation of numbness in the lips and gums, which does not subside for several hours.

In ancient authors, we frequently meet with aconite as a poison, but it has been fairly questioned whether any particular plant was designated by the term^[412]; like that of cicuta, it seems to have been a word expressive of poisons generally. The most powerful form in which this vegetable poison exists is in that of extract, or inspissated juice^[413], and, if prepared according to the improved process of Mr. Barry,^[414] it will prove highly dangerous in small doses. M. Orfila relates several fatal accidents from the ingestion of this plant; his experiments have also shewn that it will produce its effects by an external application. We agree, however, with Mr. Brodie in considering that it acts, without being absorbed, on the brain, through the medium of the nerves; and we have accordingly placed it in the first division of our classification.

The plants already enumerated are sufficient to illustrate the symptoms and physiological action of the acrid poisons of the vegetable kingdom. We shall, therefore, conclude the history of this class with some account of the nitrate of potass, which has been ranked both by FodÉrÉ and Orfila under this division of their classification.

The sensible qualities of this salt are too well known to require any description. It generally occurs crystallized in six-sided prisms, terminated by dihedral summits. It is composed of one proportional of nitric acid, and one proportional of potass. It dissolves in seven parts of water at 60°, and in its own weight at 212° Fah. Its solution is attended with a great reduction of temperature. It is permanent in the air, melts when exposed to a moderate heat; and, when cast into moulds, constitutes what is known in commerce by the name of sal prunelle. When mixed with inflammable matter it undergoes, in a strong heat, a rapid species of combustion, which, in chemical language, is termed deflagration. Concentrated sulphuric acid, when poured upon this salt in powder, decomposes it at the ordinary temperature, and disengages vapours of nitric acid, which are white, and not very abundant.

Symptoms of poisoning by Nitre.

This salt, when taken in a large dose, acts violently on the stomach and bowels, and occasions syncope and death. There are several cases recorded of its having been taken by mistake for Glauber’s salt.

On these occasions, the patients have been seized with violent vomiting and purging of blood, attended with severe pains in the bowels, and a sense of burning heat, referred to the chest and stomach; cold extremities, fluttering pulse, laborious breathing, syncope, and death. The above effects have been produced by an ounce and a half of nitre; although, as Dr. Gordon Smith has observed, the same quantity of this salt has been inadvertently swallowed without the production of such tremendous consequences.

From the experiments of Orfila, it appears that if this salt be inserted into a wound, it occasions a fatal gangrene. Its action is undoubtedly the effect of its acrid nature, destroying the vitality of the textures with which it comes in contact. It is not absorbed.

Organic lesions discovered by dissection.

In those recorded cases of death from the ingestion of nitre, the stomach has been found red, scattered over with blackish spots, and its mucous membrane disorganized.

Chemical processes for the detection of Nitre.

The property which this salt possesses of deflagrating with combustible bodies, affords a ready indication of its presence. The process also, which we have described under the history of nitric acid, (p. 312) as the one suggested by Dr. Wollaston, and adopted by Dr. Marcet in his examination of sea water, furnishes an elegant mode of ascertaining the presence of a nitric salt.

Cl. IV. NARCOTIC POISONS.

These constitute a class of vegetable poisons, less extensive, perhaps, but of far greater importance and interest, than the one we have already considered. It would not be easy to enumerate the various purposes to which the active imagination of man has applied the tribe of narcotic plants. Medicines, poisons, intoxication, and madness, lie concealed beneath their juices. They have, in their turn, arrested the pangs of disease, and inflicted death upon the unsuspecting object of hatred and revenge; they have animated the courage of the warrior, inspired the enthusiasm of the poet, soothed the sorrows of the wretched, and furnished the debauchee with a daily source of sensual gratification; effects which, although apparently incompatible with each other, may be commanded by the same substance, in a different dose. It would be foreign to the plan of this work to enter into a physiological inquiry into the modus operandi of these extraordinary agents; and the author relinquishes the labour with less regret, as he has already, in another work,^[415] very fully considered the several theories which have been advanced for its explanation.

Opium, and its Preparations.

This well known drug is the inspissated juice of the Papaver Somniferum (Polyandria Monogynia. Nat. Ord. RhoedÆÆ, Linn. PapaveraceÆ Juss.) obtained by making incisions in the half ripe capsules, at sun-set, when the night dews favour the exudation of the juice, which is collected in the morning by old women and children, who scrape it from off the wounds with a small iron scoop, and deposit the whole in an earthen pot, where it is worked by wooden spatulas in the sun-shine, until it attain a considerable degree of spissitude. It is then formed by the hand into cakes, which are laid in earthen basins to be further exsiccated.^[416] Two kinds are found in commerce, distinguished by the names of Turkey, and East Indian opium. The latter kind is regarded as being inferior to the former.

Turkey opium occurs in flat pieces, of a solid compact texture, possessing considerable tenacity; its specific gravity is 1·336, so that, when compared with concrete juices of other plants, it is heavy, being exceeded only in this respect by opoponax and gum arabic. It is of a reddish-brown, or fawn-colour, and has a peculiar, heavy, and narcotic odour; its taste is acrid, bitter, and hot. By long exposure to the air, it becomes hard, and breaks with a glimmering fracture, owing to the presence of a few saline particles. It is plastic, and when worked with the fingers is adherent to them. When brought near a lighted candle it inflames, and burns with a brilliant light, but its odour at that time is not narcotic. It is partially soluble in water, alcohol, Æther, wine, vinegar, and lemon-juice. When triturated with hot water, five parts in twelve are dissolved, six suspended, and one part remains perfectly insoluble, and resembles the gluten of wheat, but is of a dark colour. The alcoholic is more highly charged with its narcotic principle than the aqueous solution; but spirit, rather below proof, is its best menstruum.

Few vegetable substances have been more frequently, or more ably submitted to analysis; and the history of the successive steps by which our knowledge respecting its composition has advanced, must encourage us in hoping that we shall shortly be enabled to identify, by chemical tests, the presence of opium, with as little difficulty and as great precision as we are already capable of recognising a metallic poison.

According to the latest chemical views respecting the composition of this body, it may be stated to consist of the following principles, viz. resin, gum, bitter extractive, sulphate of lime, gluten, and the three lately discovered bodies, narcotine, morphia, and meconic acid.

In the year 1803, Derosne first obtained from opium a crystalline substance, which he found to dissolve in acids, but he does not appear to have instituted many experiments, for the elucidation of its nature and properties. In 1804 Seguin discovered another crystalline body, and although he described many of its properties, what appears very extraordinary, he never even hinted at its alkaline nature. Sertuerner, at Eimbeck in Hanover, had at the same time as Derosne and Seguin, obtained these crystalline bodies, but it was not until the year 1817, that he first proclaimed the existence of a vegetable alkali, and attributed to it the narcotic powers which distinguish the operation of opium; to this body, he gave the name of Morphia, and it would appear to be the same as the essential salt of Seguin. The salt of Derosne was also at first mistaken for the same principle, but the experiments of Robiquet have pointed out its distinctive properties, and it has received the name of Narcotine.

Morphia, upon which the soporific powers of opium depend, appears to exist in native combination with a peculiar acid, to which the name of meconic acid has been bestowed. The following are the essential characters of this alkaline body, when procured in a state of purity.^[417]

It crystallizes in fine, transparent, truncated pyramids, the bases of which are either squares or rectangles, occasionally united base to base, and thereby forming octohedra. It is sparingly soluble in boiling water, but dissolves abundantly in heated alcohol, giving rise to an intensely bitter solution; in Æther it is far less soluble. It has also the characters of an alkali; affecting test papers tinged with tumeric or violets, uniting with acids and forming neutral salts, and decomposing the compounds of acids with metallic oxides. It unites with sulphur by means of heat, but the combination is no sooner formed than it is decomposed. It fuses at a moderate temperature, when it resembles melted sulphur, and like that substance crystallizes on cooling; it is decomposed by distillation, yielding carbonate of ammonia, oil, and a black resinous residue, with a peculiar smell; when heated in contact with air, it inflames rapidly, and like vegetable matter, it leaves a carbonaceous residue. When analyzed by means of the deutoxide of copper, it yields carbon, hydrogen, and oxygen, the atomic proportions of which have not yet been ascertained. The nitric acid of commerce, when dropped on morphia, communicates to it a beautiful red colour. Sertuerner has given us an account of the effect of the alcoholic solution of morphia on himself, and three of his pupils; he found that repeated small doses of half a grain produced at first decided excitation; then weakness, numbness, and tendency to fainting; after swallowing vinegar while in this condition, violent vomiting was excited; in one delicate individual, profound sleep intervened, and on the following day he suffered from nausea, vomiting, head-ache, anorexia, constipation, and heaviness.^[418] This case is sufficient to shew, that although morphia possesses the characteristic powers of opium, its strength is by no means commensurate with its supposed state of concentration. When uncombined, it exerts little or no action, in consequence of its insolubility in water, and in the fluids of the stomach. When, however, it is combined with an acid, particularly the acetic, or the meconic, with the latter of which we have before stated that it exists in opium, it displays its properties in a very eminent degree. It is also very soluble in oil; and, according to the experiments of M. Majendie, the compound acts with great intensity.

The meconic acid, when separated from the residuum of the magnesian salt, as described in the process for the preparation of morphia (note p. 386) does not appear to possess any medicinal activity. Its distinguishing chemical character is, that it produces an intensely red colour in solutions of iron, oxidized ad maximum; and a deep blue, with solutions of the salts of gold. Narcotine is the salt originally obtained by Derosne, and is supposed by MM. Majendie and Robiquet to be the peculiar principle which produces the excitement experienced by those who take small doses of opium. It may be entirely removed by macerating the extract of opium in sulphuric Æther.

Symptoms of poisoning by Opium.

In considerable doses, the primary action of this substance, as a powerful and diffusible stimulant, is not apparent; for the powers of life are immediately depressed, drowsiness and stupor succeed, and these are followed by delirium, stertorous breathing, cold sweats, convulsions, and apoplectic death.

The quantity of opium necessary for the production of such effects must be regarded as relative. In no two cases can we ensure a similar result, by the administration of the same dose. But, of all the circumstances capable of modifying the power of this drug, habit is the most remarkable; in illustration of which we have only to adduce the history of the opium eater, or laudanum drinker; a species of debauchee by no means uncommon, as every London chemist can testify, for he frequently experiences considerable doubt and difficulty in distinguishing persons, to whom habit has rendered large doses of opium necessary, from such as purchase it with a view to suicide.^[419] The lowest fatal dose, to those unaccustomed to it, seems to be about four grains; but the Turk will take three drachms in the morning, and repeat the same dose at night, without any other effects than that of cheerfulness and exhilaration. This temporary impunity, however, is dearly purchased by years of suffering and sorrow. The effects of opium, says Russel, on those who have been addicted to it, are at first obstinate costiveness, succeeded by diarrhoea and flatulence, with loss of appetite, and a sottish appearance; their memories soon fail, they become prematurely old, and then sink into the grave objects of scorn and pity.^[420]

Where a person has, from accident, or design, swallowed a large dose of pure opium, or laudanum, the symptoms produced are so characteristic and striking, that the practitioner, who may be summoned to render assistance, will have no difficulty in ascertaining their cause.

Insensibility, with a scarcely perceptible respiration, although in some cases it is attended with an apopletic stertor; the countenance is livid and cadaverous; the skin cold; and the muscles of the limbs and trunk in a state of extreme relaxation. The pupils are insensible to the impression of light, and the pulse is almost imperceptible. In some stages, the patient, by being strongly shaken, may be roused for a few moments from the lethargy; there is generally a narcotic odour distinguishable in the breath. Vomiting may also take place upon the first impression of the laudanum upon the stomach; although after its action has been displayed upon the brain, it will be difficult to excite emesis by the most powerful means; the reason of which may be very satisfactorily deduced from the ingenious experiments of M. Majendie on the mechanism of vomiting; by which he proves, that without the influence of the brain, the muscles, whose actions constitute an essential part of the operation, are incapable of performing their duty, and that vomiting therefore cannot take place. This is a very important doctrine, inasmuch as it suggests to the pathologist several expedients, by which he may be enabled to occasion vomiting, by recalling the excitability of the brain. The period which will elapse, between the ingestion of the poison, and the death of the sufferer, may be stated to be from six to twenty-four hours; but it will in each case be liable to vary, not only from the quantity of opium swallowed, but from the habit and peculiar circumstances of the individual submitted to its operation.

Physiological action of Opium.

It is still a question for the decision of future physiologists, whether the narcotic principle of opium destroys the functions of the nervous system by a local impression upon the stomach,^[421] or by being absorbed,^[422] and brought into contact with the brain in the course of the circulation. We are inclined to adopt this latter opinion, and have therefore placed opium in the second division of our classification; at the same time, we think that it may occasionally produce an effect upon the nervous extremities of the stomach, and we have accordingly placed an asterisk against the word, by which we denote this double mode of operation. But, by whatever medium it may act, it is evident that it occasions death by destroying the functions of the brain; in consequence of which the muscles of respiration, no longer supplied with nervous energy, cease to contract, and the animal dies in a state of suffocation.^[423]

Of the treatment in cases of poisoning by Opium.

The first object is the evacuation of the stomach by vomiting; for which purpose, the patient should be made to swallow from fifteen grains to a scruple of sulphate of zinc; or, from five to ten grains of sulphate of copper dissolved in water; and the vomiting should be kept up for a considerable time, and urged by irritation of the fauces. Where the act of vomiting cannot be established, in consequence of the paralysed state of the nervous system, cold affusion, applied by means of a shower bath, has been said to restore the energy of the brain, and thus to render the patient susceptible of the stimulus of an emetic.^[424] Venesection has also, under the same circumstances, been greatly extolled; and, as vascular congestion in the brain is one of the effects of this poison, it is reasonable to conclude that, by unloading the vessels of this organ, we may restore its lost sensibility. Tissot has strongly recommended the practice,^[425] and the experiments of Orfila have shewn that it never aggravated the symptoms of poisoning by opium, nor accelerated the moment of death; but on the contrary, that in some instances he found that it restored the animals which would have died, if it had not been put in practice. Where the operation is performed, the blood should be drawn from the jugular vein, in preference to any other. Should these means prove insufficient to provoke vomiting, M. Orfila asks, whether one or two grains of tartarized antimony, dissolved in one or two ounces of water, might not be injected into the veins? It was formerly proposed by Boerhaave to empty the stomach of its poisonous contents, by the introduction of a syringe; an operation which, it is said, has been lately performed with success.^[426] Vinegar and vegetable acids were long considered as antidotes to opium; but the experiments of M. Orfila have clearly established that, as long as any portion of the opium remains in the stomach, these potations, so far from relieving, aggravate the symptoms of poisoning by this narcotic, in consequence of the power which they possess of dissolving it. Where, however, the opium has been expelled by vomiting, these acid drinks possess the property of diminishing the consecutive symptoms, and of thus realising the expectations which Virgil^[427] has so poetically raised,

The powers of the habit should, at the same time, be supported by brandy, strong coffee, and cordials. The sufferer should be kept awake; and, if possible, in a continued gentle motion. Dr. Currie^[428] has recommended the affusion of warm water at 106°, or 108°, for removing the stupor.

A case is recorded by Dr. Marcet, in the first volume of the Medico-chirurgical Transactions, where six ounces of laudanum were taken by a young man, and remained for five hours in the stomach before any remedies were applied for its removal; a strong dose of sulphate of copper, however, provoked vomiting, and by judicious treatment he eventually recovered.

Organic lesions discovered on dissection.

It has been very truly remarked that although the instances in which opium has proved fatal to human life have been very numerous, yet that the accounts which we have received of the appearances of the body post mortem, are by no means so satisfactory as we could desire. M. Orfila asserts that no alteration can be discovered on dissection, in the digestive canal of persons who have swallowed any narcotic poison; and that if facts contrary to this assertion be met with in various authors, it is because there have been administered irritating substances capable of producing inflammation.^[429] The lungs, however, frequently exhibit morbid phenomena; their colour is sometimes violet, and frequently a deeper red than in the natural state. Their texture is also more dense, and less crepitating; and they are marked by livid spots. The blood contained in the ventricles of the heart, and in the veins, is said to be found in a liquid state; but Orfila advances a diametrically opposite opinion, and asserts that it is frequently coagulated. The brain and its membranes often exhibit a state of vascular congestion; in the case recorded by Mr. Stanley, in the sixth volume of the Transactions of the College of Physicians, the cellular tissue of the pia mater was found to contain water.^[430]

Of the detection of Opium.

There is no mode of identifying opium, whether in a liquid or solid form, so satisfactory as that which is at once afforded by its powerful and highly characteristic odour. In fatal instances, we shall always meet with it in the contents of the alimentary canal, and in such quantities as will leave no doubt as to its nature. The chemist may also proceed to a farther examination, by obtaining morphia from its solution, by a process which we have already described under the chemical history of opium.

Henbane is an indigenous annual, frequent on waste grounds, and at the sides of roads, particularly on a calcareous soil, flowering in July. The whole of the plant is poisonous when eaten; and in the recent state the odour of the leaves occasions stupor and delirium. The root of this plant when in full vegetation is very powerful; and there are several cases on record, where it has been eaten in mistake for parsnips,^[431] which it strongly resembles in its sweet and agreeable flavour. Its operation is very analogous to that of opium; producing sickness, stupor, delirium, and coma, with dilation of the pupils.

The pulse, at first hard, gradually becomes weak and tremulous; petechiÆ frequently make their appearance, and death ensues. Late experiments have shewn that a peculiar alkaline body constitutes the active principle of this plant, and it has accordingly received, from its discoverers MM. Meissner and Brandes, the name of Hyoscyama.

Boerhaave experienced a trembling and drunkenness, in consequence of having prepared a plaister, into whose composition henbane entered as an ingredient; and the experiments of M. Orfila have shewn that it acts nearly in the same manner, whether applied upon the cellular texture, introduced into the stomach, or injected into the veins. Hence it follows that the active principle of this plant is carried into the circulation, and exerts a remarkable action on the brain and nervous system, producing an extraordinary state of delirium, which is succeeded by stupefaction. The physician will never probably be called upon to investigate a case of wilful poisoning by this narcotic; and should he be summoned to attend a person who, through mistake or accident, had swallowed it, we can hardly anticipate any peculiar mystery which requires elucidation.

There are several other species of henbane, as hyos. alb. aureus, physaloides, all of which are poisonous, although not in the same degree as the hyoscyamus niger, whose history we have just considered.

Prussic Acid. Hydro-cyanic Acid.

The Laurel (Prunus lauro-cerasus) and its distilled water. Bitter Almonds, and their essential oil.

Hydro-cyanic acid exists in a great variety of native combinations in the vegetable kingdom, and imparts to them peculiar qualities, which have been long known. It is, however, only within a few years, that this singular body has been obtained in its separate and independent form^[432]; indeed it was not until the publication of the celebrated memoir of Gay-Lussac upon this subject, in the year 1815, that its chemical composition was fully understood. In this memoir, it was clearly shewn to consist of a peculiar, gaseous, and highly inflammable compound of carbon and nitrogen, to which the name of cyanogene has been assigned, and hydrogen; the latter body acting as the acidifying principle; whence the term hydro-cyanic acid is very happily contrived to express its composition.

When obtained in its most concentrated form, by the process of M. Gay Lussac,^[433] it has the following characteristic properties, viz. At ordinary temperatures, it is liquid, colourless, and transparent; possessing an extremely powerful odour, very analogous to that of the blossom of the peach, or bitter almond tree; its taste is, at first, bland and sweetish, but afterwards pungent, bitter, and peculiar. Its extreme volatility is such, that when a drop of it is exposed to the air, on the end of a glass rod, it is rapidly crystallized. The same phenomenon takes place, if a drop be suffered to fall on a sheet of paper. Its specific gravity is ·7055; but, when in a concrete form it is only ·9, while that of its vapour is ·947. If inhaled, it produces almost immediate pain in the head, with deafness, unless very largely diluted with air or water.^[434] It is decomposed by a high temperature; and by the action even of light it is, in the course of a very short time, resolved into carbonic acid, ammonia, and carburetted hydrogen, a carbonaceous matter remaining behind.^[435] When brought near a body in a state of combustion, it instantly inflames and burns with a blue light. In water it is sparingly soluble; alcohol dissolves it copiously.

The “medicinal Prussic acid,” as it has been called, as being the preparation lately introduced into medicine,^[436] differs only from that we have just described, in its degree of concentration. It is, in fact, the Prussic acid of Scheele, and may be considered as equivalent to the preparation of Gay-Lussac diluted with six times its volume, or eight times and a half its weight, of distilled water.

The hydro-cyanic acid has been discovered, in a state of perfect formation, in a variety of vegetables, whose peculiar odour at once announces its presence; such are bitter almonds; the kernels of apricots, cherries, particularly the Cerasa Juliana, and several plums; the leaves of laurel; and peach blossoms; and the bark of the prunus padus, or bird-cherry tree. The only mineral substance, in which hydro-cyanic has yet been detected is the Fer AzurÉ of Hauy.^[437] Animal substances, although they do not contain it ready formed, yet, when treated with an alkali at a high temperature, they yield it in great abundance, in consequence of the combination of its elements.

Action of hydro-cyanic Acid as a Poison.

The experiments which have been instituted with a view to ascertain the exact effects of this substance upon animal life, very clearly prove that the acid of Gay-Lussac is one of the most active poisons in nature; and that the various vegetable bodies, into whose composition it enters, exert an energy, corresponding with the quantity of this constituent, and the degree of concentration, in which it exists. The experiments of M. Orfila were made with Prussic acid, prepared according to the process of Scheele, and consequently containing a great proportion of water, as we have already explained; and yet the effects which followed its administration were extremely energetic. From the Annales de Chimie, for October 1814, we learn that a professor of chemistry, having inadvertently left on his table a phial filled with a solution of Prussic acid in alcohol, a female servant, who had been seduced by its agreeable smell, drank a small glass-full of it, and fell dead at the end of a few minutes, as if struck by apoplexy.

The following case is quoted by Dr. Granville, from Hufeland. D. L. a robust and healthy man, aged 36 years, while about to be seized as a thief by the police officers, snatched a small sealed phial from his pocket, broke off the neck of it, and swallowed the greatest part of its contents. A strong smell of bitter almonds soon spread around, which almost stupefied all present. The culprit staggered a few steps; then, without a groan, fell on his knees, and sunk lifeless down to the ground. Medical assistance being called in, not the slightest trace of pulse or breathing could be found. A few minutes afterwards, a single and violent expiration occurred, which was again repeated in about two minutes. The extremities were perfectly cold, the breast and abdomen still warm, the eyes half open and shining, clear, lively, full, almost projecting, and as brilliant as those of the most ardent youth under violent emotion. The face was neither distorted nor convulsed, but bore the image of quiet sleep. The corpse exaled a strong smell of bitter almonds, and the remaining liquid, being analysed, was found to be a concentrated solution of Prussic acid in alcohol. Cases also stand recorded where, from imprudent exposure to the vapours of the Prussic acid, persons have exhibited all the appearances of being poisoned. Some writers assert that Scheele himself, who died suddenly, while engaged in some inquiries into the nature and formation of this acid, was affected by its deleterious qualities. Orfila relates that Scharinger, Professor at Vienna, prepared some pure concentrated Prussic acid, and having diffused a certain quantity of it upon his naked arm, he died a short time afterwards. The professor, however, did not die in consequence of this accident; it appears, upon inquiry, that he was seized with apoplexy while sitting in a coffee house in the evening.

The distilled water of the cherry laurel^[438] has been proved, by numerous awful examples, to be a most energetic poison; and from the fatal effects to which the officinal preparation of it gave rise, it was early expunged from the Pharmacopoeia of the London College. In the Philosophical Transactions for the year 1731, we shall find the history of its effects upon a woman of the name of Boyce, who, with a view to disprove an allegation, that one Mary Whaley had died in consequence of drinking a small quantity of laurel water, swallowed three spoonsful, and, afterwards, two more of the same liquid; after which she died in a very short time, without making the least complaint, and without any convulsion.

FoderÉ informs us that during the period he was pursuing his studies at Turin in 1784, the chambermaid and man servant of a noble family of that town, for the purpose of regaling themselves, stole from their master a bottle of distilled laurel water; fearful of being surprised, they hastily swallowed several mouthsful of it; but they soon paid the price of their dishonesty, having almost instantly expired in convulsions. Works on Toxicology also abound with the relation of experiments, made by numerous physiologists on different animals, with this deleterious liquid. Amongst the experimentalists we may enumerate the names of Madden, Mortimer, Browne, Langrish, Nicholls, Stenzelius, Heberden, Watson, Vater, Rattrai, the AbbÉ Rozier, Duhamel, Fontana, and Orfila. In this country we have had several fatal cases of poisoning by laurel water. In the year 1782, Dr. Price, of Guildford, having professed to have converted mercury into gold, offered to repeat his experiments before a competent tribunal, but the unfortunate philosopher put a period to his existence before the day appointed for his exhibition, by a draught of laurel water; a mode of death which had been, no doubt, suggested by the celebrated trial of Donellan, for the murder of Sir Theodosius Boughton, that had taken place in the preceding year, and left a strong impression upon the public mind; and whose details, it has been justly observed, are not more important from the elucidation of the effects of this poison, than from the strange display of professional testimony to which it gave origin, (see Appendix, page 243.) There are those who still profess to believe that the prisoner was unjustly convicted upon that occasion; Dr. Male states, without the least reserve, that it was neither proved that the deceased was poisoned, nor that any poison had existed.^[439] We feel no difficulty in declaring that we hold a directly opposite opinion; and we consider that many of the weaker points of professional evidence delivered on the trial, have received powerful support and elucidation from the experiments and observations of later physicians.

Nor are the leaves of this plant wholly free from danger; it is true that they have, for many years, been in general use among cooks, to communicate an almond or kernel-like flavour to custards, puddings, creams, blanc-mange, and other delicacies of the table; but the custom has not always been harmless; a fact with which it behoves the forensic physician to be acquainted. In some parts of the continent milk is boiled with one or two leaves of the cherry-laurel in it, and Ingenhouz states that he saw people much affected by it. In the Literary Chronicle (no. xxii, p. 348, 1819) we find the following illustrative case: “Several children at a boarding-school, in the vicinity of Richmond, having partaken of some custard flavoured with the leaves of the cherry-laurel, four of them were taken severely ill in consequence. Two of them, a girl of six, and a boy of five years of age, fell into a profound sleep, out of which they could not be roused for ten hours, the other two complained of severe pains in the epigastric region. By proper medical treatment, they all recovered, after an illness of three days.”

The essential oil of bitter almonds is equally poisonous; and the water distilled from them is highly dangerous if incautiously taken. Duvignau and Parent instituted some experiments upon themselves to ascertain this fact; they commenced by taking six drops of the water distilled three times, in an appropriate vehicle, without producing any other than a transient impression. On taking eighteen drops, however, vertigo was experienced, and a disposition to sleep, accompanied with a tingling of the ears and dimness of sight. When the dose was increased to twenty-two drops, alarming symptoms followed, such as convulsions, and vomiting; which, although the experimenters succeeded in allaying by antispasmodics, cured them completely of any ulterior wish to ascertain how far this substance might be deleterious. A drachm of the distilled water of bitter almonds has killed a moderate sized dog. The essential oil is proportionally more active; Mr. Brodie^[440] found that one drop, when applied to the tongue of a cat, killed it in five minutes; no sooner did the poison come in contact with the organ than the animal was seized with convulsions. When two drops of the same oil were injected with half an ounce of water into the rectum of a cat, it was not seized for two minutes, but it died, as in the former experiment, after the expiration of five minutes. While engaged in this inquiry, Mr. Brodie dipped the blunt end of a probe into the essential oil, and applied it to his tongue, with the intention of tasting it, and not having the least suspicion that so small a quantity could produce any of its specific effects on the nervous system; but scarcely had he applied it, when he experienced a very remarkable and unpleasant sensation, which he referred chiefly to the epigastric region, but the exact nature of which he could not describe, because he knew nothing similar to it. At the same time there was a sense of weakness in his limbs, as if he had not the command of his muscles; and he thought that he should have fallen. The fascinating liqueur noyau, crÉme de noyau, is indebted for its flavour to the essential oil of the bitter almond, or peach; and is undoubtedly deleterious if taken in excess. In the Journal des Debats, for 1814, we find that the late Duke Charles de Lorraine had nearly lost his life from swallowing some drops of eau de noyau too strongly impregnated with the essential oil of peach kernels.

The bitter almond itself, in consequence of the manner in which its deleterious principle is modified by the natural state of combination in which it exists with sweet oil and albumen, does not produce an effect corresponding with the proportion of essential oil which it yields. The experiments of Orfila, however, prove that the almond, in doses of a drachm, is destructive to cats; and there can be no doubt but that it would be equally deleterious to the human species; but the quantity required for the production of such an effect must ever prevent the bitter almond from becoming either the accidental or criminal instrument of death.

Physiological action of Prussic acid.

The numerous experiments, which have been made with this poison, have clearly established that its action is upon the nervous system, whose energies it would seem to extinguish without any ostensible injury to respiration and circulation; for in all those animals which were killed by it, in the experiments of Orfila, Brodie, and others, the heart was found acting regularly, and circulating dark coloured blood, and in some cases this phenomenon was visible for many minutes after the animal was in other respects apparently dead. Orfila considers that he has fully demonstrated that these effects depend on the absorption of the poison, and its transmission to the brain through the medium of the circulation. We have accordingly placed Prussic acid in the second division of our classification. The essential oil of bitter almonds would, according to the experiments of Mr. Brodie, appear to act through the medium of the nerves, and it has accordingly been referred to our first division. This is undoubtedly an anomaly, which it is not easy to reconcile; the experiments, however, which led Mr. Brodie to the conclusion appear to us to warrant such a deduction; the instantaneousness with which the poisonous effects were produced, and the fact of its acting more speedily when applied to the tongue, than when injected into the intestines, although the latter presents a better absorbing surface, seem to oppose the idea of the oil requiring to be absorbed, before it can display its energies. M. Vogel, of Munich, has lately discovered some facts respecting the composition of this oil, which may perhaps hereafter lead to the true explanation of this apparent anomaly; this distinguished chemist succeeded in separating the Prussic acid from the volatile oil with which it is combined, by agitating the whole in a concentrated solution of potass, and distilling to dryness; the oil volatilized together with the water, while the residuum in the retort was found to contain cyanide of potassium. The oil, thus separated from the Prussic acid, is without odour, and heavier than water; its taste is extremely acrid and burning; in order to discover whether it was still poisonous, M. Vogel put a drop of it on the tongue of a sparrow, when it died in a few seconds, after a very violent convulsion; he also poisoned a dog, two months old, with four drops of it; whence he concludes that the volatile oil, divested of its hydro-cyanic acid is still a poison, although less energetic than that which has not undergone such a change. Do there exist then two independent principles of activity in the bitter almond? If such a fact were established it would not be solitary, for we shall hereafter shew that the energies of tobacco are dependant upon an analogous arrangement; and that our ignorance of the fact, at first, occasioned apparent anomalies, as embarrassing as those which at present involve the physiological history of the oil of almonds.

Antidotes.

Orfila, in his celebrated Toxicology, informs us that vinegar, or the vegetable acids; coffee; a solution of chlorine in water; camphor; emollient drinks; and bleeding, have been successively, but not successfully recommended.^[441] With respect to the first of these pretended antidotes, it deserves notice, that instead of palliating the symptoms, it actually quickens, and gives more energy to the action of the poison. Coffee, as far as it may stimulate, might be employed with advantage; but its powers are not sufficient to meet the exigency of the case. Bleeding seems decidedly a fatal measure. The authors of the paper on Prussic acid, inserted in the American Recorder, consider at length the claims of every substance which has been proposed as an antidote to it; and they conclude by saying that, we are entirely ignorant of a counter-agent of this poison. There is every reason, says Dr. Granville, to believe that the Prussic acid taken in large quantities, and in its concentrated state, is partially, if not wholly absorbed ere it reaches the stomach;—else how happens it that scarcely a minute after its exhibition, I have, in common with others, been unable to detect its presence within that organ. If so, then all chemical attempts must be nugatory, no decomposition, or fresh combinations can be produced to render it harmless; nor will an emetic, although so much recommended, be of much more service in freeing the system of its presence. But although chemical remedies are thus shewn to be of no avail, we may derive from the class of vital agents some powerful antidotes; all medicines taken from the class of diffusible stimuli will be useful in supporting the powers of the system against the sedative influence of the poison. Hot brandy and water, with ammonia, camphor, and other similar stimulants, are the resources to which we should fly upon such occasions.

Organic lesions discovered on Dissection.

The recorded dissections of persons, who have been poisoned by Prussic acid, are too few and vague to furnish any satisfactory generalization. In the case related by M. FoderÉ, of two servants who died after a draught of laurel-water, the dead bodies were carried to the University at Turin, and examined, when the stomach was found slightly inflamed, but the other parts were in a sound state. We feel much hesitation in giving credit to this report, the death was too immediate to allow the access of inflammation; we are rather disposed to consider the appearances of the stomach to have arisen from that species of sanguineous congestion, which we have before alluded to, as sometimes occurring in cases of sudden death. In other cases the coats of the stomach are said to have been black and relaxed; the vessels of the brain injected; the lungs have also been described as presenting unnatural congestions, and purple spots; and the smell of Prussic acid seemed as if it pervaded the whole system, and was embodied, as it were, with the very substance of the muscles. In other cases, again, not the slightest trace of any morbid appearance could be discovered. Some authors have stated that in cases of death by this poison the cornea of the eye does not collapse, but retains its fulness, and even its lustre, for a considerable period.

Chemical processes by which the presence of hydro-cyanic acid may be ascertained.

The strong odour yielded by the body on dissection, will furnish a satisfactory proof of the presence of this poison. Instances may occur, when the practitioner will be called before a tribunal to answer, from his professional knowledge, whether a particular case of death can have happened from the action of the hydro-cyanic acid, or any of the compounds in which it may enter as an ingredient; it therefore becomes an object of great importance to inquire whether any farther tests might be made subservient to our purpose. Dr. Granville, who has directed a great share of his attention to the history of this poison, has given some directions upon this point, which appear to us to be useful and judicious; we shall, therefore, present them to our readers. “After collecting the blood contained in the ventricles of the heart, a portion of the contents of the stomach, and of the superior intestines, together with a certain quantity of any fluid which may chance to be present within the cavity of the head, chest, or abdomen; and having agitated the mixture for some time in distilled water, and filtered the liquid, taking care to keep the whole at a low temperature, proceed to the following experiments.

A. To a small quantity of the liquid add a few drops of a solution of caustic potass in alcohol.

B. To this, a few drops of a solution of sulphate of iron must be added, when a cloudy and reddish precipitate, of the colour of burnt Terra-Sienna will fall down.

C. Some sulphuric acid is now to be introduced into the tube, when the colour of the precipitate will instantly change to that of a bluish-green, which by a permanent contact with the atmosphere, becomes gradually of a beautiful blue, assuming at the same time a pulverulent aspect.

A. Treat the filtered liquid with carbonate of potass.

B. Add a solution of sulphate of iron with a small quantity of alum: a precipitate, as in the former method, will fall down, which if treated by free sulphuric acid, will also become blue and pulverulent. During this latter part of the experiment, there is a disengagement of carbonic acid.

Evidence may be pushed still farther, and the existence of the Prussic acid proved in a most positive manner by decomposing the precipitate, above described, and which is a true Prussian blue, so as to separate the acid. For this purpose, heat the precipitate with an equal quantity of tartaric acid, in a glass retort, at the temperature of 150°, when the hydro-cyanic vapours will soon exhale from the mixture, and may be received in water.”^[442]

Cl. V. NARCOTICO-ACRID POISONS.

We have already stated our objections to this division, and our apology for adopting it. See page 205.

Deadly Nightshade. Atropa Belladonna.

(Pentandria Monogynia. Nat. Ord. LuridÆ Linn. SolanaceÆ. Juss.)

This plant is an indigenous perennial, found in many parts of Great Britain, particularly in shady places where the soil is calcareous, in large ditches, and on the edge of hilly woods; flowering in June, and ripening its berries in September. Every part of the plant is poisonous; and numerous instances have occurred where children, and the ignorant, or those suffering from hunger, allured by the beautiful and tempting appearance of the berries, have fallen victims to their deadly power. The root of this plant partakes also of the same qualities as the leaves and berries, but is perhaps less virulent.

The inspissated juice (Extractum BelladonnÆ Pharm. Lond.) is also extremely poisonous, when properly prepared; but, as usually met with in commerce, it is of very variable strength; when prepared according to the improved process of Mr. Barry, its activity is so considerable that a dose of two grains is followed by unpleasant effects. (See an account of its effects in the Pharmacologia, vol. 2, p. 199.) M. Brandes has lately ascertained that the active principle of this plant is a peculiar alkaline body, to which he has assigned the name of atropia.

Symptoms of poisoning by Belladonna.

Shortly after the ingestion of the berries, leaves, or root, of this plant, the patient complains of extreme dryness of the lips, tongue, palate, and throat; the deglutition becomes difficult, and the pupil of the eye immoveably dilated; nausea, rarely followed by vomiting; symptoms of intoxication succeed, accompanied with fits of laughter, dreadful ravings, violent gestures of the body, and continual motion of the hands and fingers; sometimes the patient sinks into a state of fatuity, but rarely of stupor; redness and tumefaction of the face, a low and feeble pulse, paralysis of the intestines, livid spots on different parts of the body, profuse sweats, convulsions, and death. In the cases where recovery has taken place, there has been an insensible restoration to health and reason, without any recollection of the preceding state.

The results of the experiments of Orfila authorise us to arrange the nightshade under the second division of our classification; for it is evidently absorbed, carried into the circulation, and is thus enabled to act upon the nervous system, and particularly on the brain. At the same time it exerts a local action upon the stomach, although less violent than that occasioned by the acrid poisons. It, moreover, appears on some occasions to act directly through the medium of the nerves, like those substances which constitute our first class; or else how shall we explain the fact of the pupil of the eye becoming permanently dilated, by the contact of the belladonna with the tunica conjunctiva? It would, therefore, appear that this plant unites within itself all the three great modes of action, upon which we have attempted to found our physiological arrangement of poisons, as expressed by the tabular classification at page 207.

Organic lesions discovered on dissection.

The bodies of those who have perished by belladonna, are extremely prone to decomposition; they soon putrefy, swell remarkably, and are covered with livid spots; blood flows from the mouth, nose, and eyes, and the stench is insufferable. The stomach and intestines will sometimes display extensive marks of inflammation, extending in some cases to the mesentery and liver; and several cases are recorded in which the stomach appeared ulcerated. The lungs are usually found livid, gorged with venous blood, and studded with black spots; the heart has been also observed to be livid.

Where the berries of this plant have been swallowed, we shall generally detect them in the matter vomited; or, in the event of death, in the stomach, on dissection, for they would appear to be very indigestible; in a case of poisoning by this plant, recorded in the history of the French Academy for the year 1706,^[443] the stomach was found to contain some berries of the belladonna crushed, and some seeds. Where the quantity of the plant is sufficient, we may proceed to identify it, by obtaining atrophia^[444] from it. For this purpose, the leaves, or the crushed berries, or any other part of the suspected plant, must be boiled in distilled water; the decoction must then be pressed out, and filtered; after the albumen has been thrown down by a little sulphuric acid, potass must be added as long as any precipitate is produced; when the precipitate is to be washed in pure water, re-dissolved in muriatic acid, and re-precipitated by ammonia. This last result will be atropia. It is white, and collects in acicular crystals, insipid, little soluble in cold water, or even in alcohol, but very soluble in this latter fluid at a boiling temperature, from which, however, it is deposited on cooling.

Stramonium. Thorn-Apple. James-town Weed.

Datura Stramonium (Pentandria Monogynia. Nat. Ord. SolanaceÆ, Linn. SolaneÆ, Juss.)

The thorn apple is an annual plant, a native of America, which gradually diffused itself, from the south to the north, and is now naturalized to this country, and is to be found very commonly about London growing on dunghills, and by road sides. It flowers in July and August. Every part of this plant is a strong narcotic poison, producing vertigo, and most of those symptoms which we have described as the effects of belladonna, although the former plant appears to excite the brain more violently. Dr. Barton mentions the case of two British soldiers, who ate it by mistake, for the chenopodium album; one became furious, and ran about like a madman; and the other died, with the symptoms of genuine tetanus. In the fifth volume of the Edinburgh Medical and Philosophical Commentaries, two cases are related by Dr. Fowler; and others are to be found in the writings of Haller, Krause, Sproegel, Gmelin, and Orfila, illustrative of the effects of this plant upon the human species. There is reason to believe that this plant has been long known, and that it has been very generally used by uncivilized nations, on account of the narcotic effects which it occasions.

Tobacco. Nicotiana Tabacum.

(Pentandria Monogynia. Nat. Ord. LuridÆ, Lin. SolaneÆ, Juss.)

Tobacco is an annual plant, a native of America, from whence it was imported into Europe. We learn from Humboldt that it has been cultivated from time immemorial by the native people of the Oroonoko; and was smoked all over America at the time of the Spanish conquest. Hermandez de Toledo sent it into Spain and Portugal in 1559, when Jean Nicot^[445] was Ambassador at the court of Lisbon, from Francis II, and he transmitted, or carried either the seed, or the plant to Catherine de Medicis, as one of the wonders of the new world, and which, it was supposed, possessed virtues of a very extraordinary nature. This seems to be the first authentic record of the introduction of this plant into Europe. In 1589 the Cardinal Santa Croce, returning from his nunciature in Spain and Portugal to Italy, carried thither with him tobacco; and we may form some notion of the enthusiasm with which its introduction was hailed, from a perusal of the poetry which the subject inspired. It is said that the smoking tobacco was first introduced by Sir Walter Raleigh on his return from America; and the avidity with which the custom was immediately adopted is shewn by the philippic written against it by King James, entitled the “Counterblaste to Tobacco.”

As an object of Medical Jurisprudence, its claims to our attention are numerous and important; not only as having occasionally been the means of destroying human life, but as furnishing, in its most romantic history, a striking illustration of the triumph of popular opinion over a series of legislative enactments^[446] which had no other origin than that of ignorance and prejudice.

Tobacco was at one period of our history raised to a considerable extent in Yorkshire; but the cultivation of it for the purposes of trade have been long prohibited; and this country, as well as the greater part of Europe, is chiefly supplied from Virginia, where the plant is cultivated in the greatest abundance. The recent leaves do not possess any considerable odour, nor have they much flavour; when dried, however, their odour becomes strong, narcotic, and somewhat foetid; their taste bitter, and extremely acrid. We have stated, upon another occasion,^[447] that tobacco would appear to contain two independent elements of activity, an essential oil, and a proximate principle, of an acrid nature, to which Vauquelin has bestowed the name of Nicotin. The essential oil is an extremely virulent poison. Mr. Barrow, speaking of the use which the Hottentots make of it for destroying snakes, says, “A Hottentot applied some of it from the short end of his wooden tobacco-pipe to the mouth of a snake, while darting out his tongue. The effect was as instantaneous as an electric shock; with a convulsive motion that was momentary, the snake half untwisted itself, and never stirred more; and the muscles were so contracted, that the whole animal felt hard and rigid, as if dried in the sun.” The author has ventured a conjecture in his Pharmacologia,^[448] with respect to this virulent oil, which he takes this opportunity of repeating, that “the juice of cursed hebenon,” by which, according to Shakspeare, the King of Denmark was poisoned, was no other than the essential oil of tobacco.

In the first place, the learned commentator Dr. Gray observes, that the word here used (hebenon) was more probably designated by a metathesis, either of the poet or transcriber, for henebon, i. e. henbane. Now it appears from Gerarde that tabaco was commonly called “henbane of Peru” (Hyoscyamus Peruvianus); and when we consider how high the prejudice of the court ran against this herb, as so strikingly evinced by the ‘Counterblaste’ of King James, it seems very likely that Shakspeare, who was fond of playing the courtier, should have selected it, as an agent of extraordinary malignity, upon such an occasion. No preparation of the hyoscyamus with which we are acquainted, would produce death by an application to the ear; whereas the essential oil of tobacco might, without doubt, occasion a fatal result. The term distilment has also called forth a remark from Steevens, which is calculated to add a little farther weight^[449] to our conjecture; “surely” says he, “this expression signifies, that the preparation was the result of a distillation.”

The leaves of tobacco, whether whole, or reduced to powder, as they are daily met with in commerce, or in the form of infusion in water or wine, or in the state of smoke, are endued with poisonous properties of extreme energy. Their administration is shortly followed by vertigo; severe nausea; vomiting; a general tremor of the body, which is rarely the result of any other poison; cold sweats; syncope; and death. The author remembers witnessing a lamentable exemplification of the action of tobacco upon a person labouring under a strangulated hernia. The patient had been under the care of a medical practitioner in the vicinity of London, who after repeated and fruitless efforts to return the intestine, injected an infusion of tobacco into the rectum, and sent him in a carriage to the Westminster hospital, for the purpose of undergoing the operation; but the unfortunate man expired very shortly after his arrival, in consequence of the effects of the tobacco clyster. The external application of tobacco, in the form of cataplasm, or infusion, will occasion all the effects above related. A woman applied to the heads of three children afflicted with tinea capitis, a liniment consisting of powdered tobacco and butter, soon after which they experienced vertigo, violent vomiting, and fainting.^[450]

It was formerly a practice to inject the smoke of tobacco into the anus, by means of a bellows of a peculiar construction, in cases of suspended animation, with a view to stimulate the rectum, and thereby to revive the vital powers; we have already commented upon this most dangerous and mistaken notion, (see page 88.)

In the process of smoking tobacco, the oil is separated, and being rendered empyreumatic by heat, it is thus applied to the fauces in its most active form; whence vertigo, nausea, and all its characteristic symptoms speedily arise upon that occasion; although the system becomes easily habituated to the action of this narcotic, and we continually see a large portion of the community using it daily, in various ways, and in great quantities, as a luxury, without experiencing any other bad effect than that which arises from their inability to relinquish the habit.

The well known errhine, snuff, is prepared from the dried leaves of tobacco, and possesses all the powers of the plant. The celebrated Santeuil experienced vomiting and horrible pains, amidst which he expired, in consequence of having drank a glass of wine, into which some Spanish snuff had been introduced.^[451]

Physiological action of Tobacco.

The deleterious effects of this plant appear to depend on an especial action upon the nervous system; but farther experiments are required to establish through what medium its powers are conveyed to the sensorium. Orfila concludes that the active part of the plant is absorbed, and carried into the circulation. Mr. Brodie’s experiments, however, would lead to the conclusion that it operates through the medium of the nerves; and, what is extremely singular, they shew that the essential oil operates very differently from the infusion of tobacco; for that while the former appears to act exclusively on the brain, leaving the power of the circulation unimpaired, the latter acts on the heart at once, suspending its action even before the animal ceases to respire, and kills by producing syncope. This apparent anomaly at first led Mr. Brodie, as he has since informed the author, to suspect the accuracy of his experiments; but their careful repetition rendered this impossible. We suggested to him, whether a probable explanation might not be found in the late chemical results respecting the composition of tobacco, which seemed to shew that this plant possesses two active elements.^[452]

Hemlock. Cicuta.^[453]

Conium^[454] Maculatum (Pentandria Digynia. Nat. Ord. UmbellatÆ.)

Hemlock is a biennial, umbelliferous, indigenous plant, growing very commonly about the sides of fields, under hedges, and in moist shady places. It is at once distinguished from other umbelliferous plants, with which it may be confounded, by its large and spotted stem, the dark and shining colour of its lower leaves, and their disagreeable smell; which, when fresh and bruised is said to bear a strong resemblance to that of the urine of a cat. Many^[455] cases of persons who have been poisoned by this plant are to be found in the writings of different toxicologists. The extract, if properly prepared, is a very energetic substance, and gives rise, in large doses, to all the symptoms which we have so often described as the result of narcotic poisons. In those fatal cases, where the bodies have been examined, post mortem, inflammation of the stomach, and sanguineous congestion in the brain, have been the most prominent phenomena. It would appear that the active element of this plant is absorbed and carried into the circulation, through which medium it exerts its action on the nervous system, and more particularly on the brain. At the same time it seems to excite a local irritation, capable of producing an inflammation more or less violent. The best antidote is vinegar, after the stomach has been evacuated, and the cerebral excitement reduced by bleeding and purging.

The Cicuta Virosa, or water hemlock, with which the conium maculatum has been often confounded, is still more virulent; it is however to be distinguished from the latter, by having its hollow roots always immersed in water, while those of the conium never are. M. Orfila has related several cases of poisoning by the water hemlock.

Nux Vomica.

This is the seed of the Strychnus Nux Vomica (Pentandria Monogynia, Nat. Ord. ApocyneÆ, Juss.)

The tree^[456] which produces these seeds grows in Ceylon, upon the coast of Coromandel, and in Malabar. The nux vomica is round and flat, about an inch broad, and nearly a quarter of an inch thick, with a prominence in the middle on both sides, of a grey colour, covered with a kind of woolly matter, but internally hard and tough. The kernel discovers to the taste a considerable bitterness, but makes little or no impression on the organs of smell. There is a popular belief that this substance is poisonous to all animals, except man. Instances, however, are not wanting to illustrate its deleterious effects upon the human species. It proves fatal to dogs in a very short period; it has also poisoned hares, foxes, wolves, cats, rabbits, and even some birds. Loureiro relates that a horse died in four hours after taking a drachm of the seed in an half roasted state. Its effects, however, on different animals, and even on those of the same species, are somewhat uncertain, and not always in the proportion to the quantity given. With some animals it produces its effects almost instantaneously: with others, not until after the lapse of several hours, when laborious respiration, followed by torpor, tremblings, coma, and convulsions usually precede the fatal spasms, or Tetanus, which so especially distinguishes the operation of this poison. Hoffman reports the case of a young girl of ten years of age, who, labouring under an obstinate quartan fever, took, at two doses, fifteen grains of nux vomica, and died very shortly afterwards. MM. Pelletier and Caventou have discovered in these seeds, a peculiar proximate principle, to which their virulence is owing; it was originally named Vauqueline, in honour of the celebrated French philosopher, but in deference to the opinion of the French Academy of Sciences, the discoverers have substituted the name Strychnia,^[457] because “a name dearly loved, ought not to be applied to a noxious principle!”

Strychnia is highly alkaline, and crystallizes in very small four-sided prisms, terminated by four-sided pyramids; its taste is insupportably bitter, leaving a slight metallic flavour, and is so powerful as even to be perceptible when a grain is dissolved in eighty pounds of water;^[458] it has no smell. So extreme is its activity upon the animal system, that in doses of half a grain it occasions serious effects, and in larger ones, convulsions and death. It is, perhaps, the most powerful, and, next to hydro-cyanic acid, the most rapid of poisons. M. Majendie has killed a dog with one-eighth of a grain; and the editor of the Edinburgh Medical and Surgical Journal has seen one die in two minutes after the injection of one-sixth of a grain into the cavity of the pleura.

Nux vomica is supposed by Orfila to exert a specific action on the spinal marrow, thereby producing tetanus, immobility of the thorax, and consequently asphyxia, of which the animal dies. That this effect is produced by the absorption of the poison, and its passage into the circulation, is clearly established by the interesting and important experiments of M. Majendie.^[459]

Cocculus Indicus.

This is the fruit of a shrub (Menispermum Cocculus) which grows naturally in the sand, in the midst of the rocks, on the coast of Malabar, in the island of Ceylon, and in other parts of the East Indies. The berries are imported into this country in a dry and shrivelled state. In India they are employed for killing fish, which they intoxicate and poison, when thrown into fish ponds. M. Goupil, a physician of Nemours, communicated to the Society of Medicine some interesting facts on the subject of this poison;^[460] and he has shewn that it is not only destructive to fishes, but also to different carnivorous quadrupeds, and, very probably, to man. He also states that the poisonous principle of this substance is not sensibly changed by the gastric juices, and the vital action of the organs of digestion; but, on the contrary, that it passes into the absorbent system with all its properties unimpaired; and that the flesh of those fishes which have eaten it, irritates the stomach and bowels of the animals to which it is given, nearly in the same manner as the Cocculus Indicus itself. All the fishes who eat it do not die in an equal space of time. Roach, pollard, breme, perch, tench, and barbel, are affected in an order corresponding with that in which they are here arranged; the roach is killed the easiest of all; the barbel is the last to die, and is moreover said to be, of all fish, the one whose flesh the most frequently occasions accidents in those animals who eat it; probably, says M. Goupil, because these fish, taking a longer time to die, the poison is longer subjected to the action of the digestive juices, and a considerable quantity of it is consequently absorbed.^[461]

Late experiments^[462] have shewn that the active principle of the cocculus Indicus is an alkaline body, crystallizable, bitter, and extremely poisonous; to this principle, M. Boullay has given the name of picrotoxine, and the experiments of M. Orfila have confirmed the idea of its constituting the only active element of the seeds.

Poisonous Mushrooms.

The common mushroom, or champignon, (Agaricus Campestris) has been long esteemed an article of epicurean delicacy; and is eaten in its fresh state either stewed or boiled; and as a preserve, in the form of pickle or powder. Its juice, moreover, furnishes the sauce so well known by the name of ketchup,^[463] or catsup. Mr. Miller informs us that the true eatable mushroom may be easily distinguished from the poisonous and unpleasant species by the following characters. “When young, it appears of a roundish form, smooth, like a button; which together with its stalk, is white, especially the fleshy part of the button; the gills within, when broken, are livid. As it grows larger, it expands its head by degrees into a flat form; the gills underneath are at first of a pale flesh-colour, but become blackish on standing.” There are besides a vast number of species which may be eaten with perfect impunity; the Agaricus Procerus, or tall mushroom, is sometimes exposed for sale in Covent Garden market, and is quite harmless; although, when preserved in pickle, it is very apt to run into the vinous fermentation. With equal safety the Agaricus Pratensis, or Scotch bonnet, as it has been called, may be eaten; it occurs in those patches which are well known by the popular name of fairy rings. The Agaricus deliciosus is considered by Withering to have been the mushroom which formed the vehicle of poison to Claudius CÆsar, as related at page 134 of this volume, and which has been celebrated by the satiric pen of Juvenal, and the epigrammatic muse of Martial; a species of mushroom, observes Withering which is still highly esteemed in modern Italy, as it was in ancient Rome. SchÆfer and Clusius, however, consider the plant in question to have been the Agaricus Xerampelinus, a species which although esculent, has a strong, and by no means an agreeable flavour. The common champignon has never, as far as we can learn, produced any mischief, although a popular opinion prevails that soil, shade, and other local circumstances, may render it virulent. If any unpleasant symptoms were to follow its ingestion, we should be inclined to regard them as the result of the peculiar idiosyncrasy of the individual, rather than as the consequence of an absolute poison; indeed a question has been raised how far such an explanation may not apply to all the cases of poisoning from this tribe of plants; for it has been observed that in many parts of Europe several of those species of mushroom are eaten with impunity, that are regarded by us as most virulent poisons; of this number we may reckon the Agaricus Piperatus, or Pepper Agaric, which is eaten in great quantity by the Russians, who fill large vessels with them in the autumn, seasoning or pickling them with salt, and then eating them in the ensuing lent.^[464] There is, however, too much direct evidence in favour of the existence of an acrid poison in certain Agarics, to allow the supposition of their being relative^[465] in their operation, as exemplified in the history of the Agaricus Muscarius, or Bugagaric, which is so called from its power in destroying these insects; and for which purpose the inhabitants of the north of Europe infuse it in milk, and set it in their windows. It constitutes the Mouchomore of the Russians, Kamtschadales, and Koriars, who use it for the sake of intoxication; upon some occasions they eat it dry, but generally it is steeped in a liquor made with the Epilobium Angustifolium; upon drinking which, they are seized with convulsions in all their limbs, followed by raving delirium: an effect which renders it a desirable potation^[466] to those who intend to accomplish any desperate act, or premeditated assassination. It is also stated that those who drink the urine of persons intoxicated by this agaric, experience the effects of the mushroom. Withering,^[467] who has been very assiduous in the display of this species, acknowledges ten varieties, all of which are natives of Britain. The Agaricus Semi-globalus of this botanist, and which is identical with the A. Glutinosus of Curtis, is extremely poisonous, and has proved fatal in several instances in this country. There are a great many other species equally destructive, but notwithstanding the labour that has been bestowed upon this branch of natural knowledge, much remains to be explained. The ancients appear to have taken considerable pains in discriminating between esculent and poisonous fungi; among the moderns, Clusius has furnished a mass of information. Withering has described with great botanical minuteness and accuracy the different species and varieties of this extensive genus of the cryptogamia; but he has failed in pointing out the poisonous, from the esculent and harmless species. Orfila, in his late lessons on Poisons,^[468] has bestowed considerable labour with a view to establish a practical distinction, and has enriched his work with highly illustrative engravings. Upon the present occasion, it is scarcely necessary to observe, that it would be foreign to the plan of this work to enter into such botanical details as the full elucidation of this subject would require; the research would, in itself, occupy a quarto volume; we must therefore rest satisfied with general observations. The following indications should excite a suspicion of mushrooms. A marshy and shady locality; an ugly or lurid physiognomy; a glairy or moist surface; a change of colour when cut, and a soft, porous, and moist texture; a virulent smell; a bright colour, or a combination of distinct colours. We ought also to reject as dangerous all those which have bulbous and soft stems, or which have fragments of skin glued to their surface.

Symptoms of poisoning by Mushrooms.

Exhilaration of spirits, laughter, vertigo, sickness, griping pains, vomiting, and purging, suffusion of the eyes, stupor, cold sweats, syncope, convulsions, death. Numerous records of sickness and death might be adduced in illustration of this subject. The celebrated musician, Schobert, and, with the exception of one child, his whole family, together with a friend and a physician who dined with him, were all fatally poisoned by a dish of mushrooms, which he had himself gathered in the fields of Saint Gervais, a village in the environs of Paris. It is not known to what species the plants belonged. In the Gazette de SantÉ, for August 1812, we have the following narrative. “M. Dufour, a physician of Montargis, gathered in the neighbouring forest some mushrooms, which were stripped of their skin, and their stem, cut into pieces, and cooked in their juice with butter and fine herbs, under a camp oven. They were served up at table. The servant girl, aged twenty years, who had eaten the greatest quantity, very shortly complained of confusion of the head, giddiness, and a slight heaving of the stomach; her face was red and inflamed, the eyes starting and lively, the pulse full and undulating. The eldest daughter of M. Dufour experienced the same symptoms without any nausea. A little child, eighteen months old, that had only eaten some bread dipped in the gravy, slept quietly for sixteen hours, contrary to his usual custom, and exhibited no other remarkable phenomenon. The other child, aged eleven years, complained of confusion of the head and intoxication; the parents did not experience any ill effects. Upon investigation it was discovered that two mushrooms of the Agaricus Muscarius, having been confounded with the proper one, had entered into the composition of the dish.”

Amongst the cases which have occurred in this country, we may particularize that related by Mr. E. Brande, in the third volume of the London Medical and Physical Journal, p. 41, “J. S. gathered early in the morning of the third of October, in the Green Park, what he supposed to be small mushrooms; these he stewed with the common additions in a tinned iron^[469] saucepan. The whole did not exceed a tea-saucer full, which he, and four of his children ate the first thing, about eight o’clock in the morning, as they frequently had done without any bad consequence; they afterwards took their usual breakfast of tea, &c., which was finished about nine, when Edward, one of the children (eight years old) who had eaten a large proportion of the fungi, was attacked with fits of immoderate laughter, nor could the threats of his father or mother restrain him. To this succeeded vertigo, or stupor; the pupils of his eyes were, at times, dilated to nearly the circumference of the cornea, and scarcely contracted at the approach of a strong light; his breathing was quick, his pulse very variable, at times imperceptible, at others too frequent and small to be counted, latterly very languid; his feet were cold, livid, and contracted; he sometimes pressed his hands on different parts of his abdomen, as if in pain, but when roused and interrogated respecting it, he answered yes, or no, evidently without any relation to what was asked. About the same time the father, aged forty, was attacked with vertigo, and complained that every thing appeared black, then wholly disappeared; to this succeeded loss of voluntary motion and stupor; in about ten minutes he gradually recovered, but complained of universal numbness and coldness, with great dejection, and a firm persuasion that he was dying; in a few minutes he relapsed, but recovered as before, and had several similar fits during three or four hours, each succeeding one being less violent, and with longer intermission than that preceding. Harriet, twelve years old, who had eaten but a very small quantity, was also attacked at the time with slight vertigo. Charlotte, a delicate little girl, ten years of age, who had eaten a considerable quantity, was suddenly attacked in the presence of Dr. Burges and myself, with vertigo and loss of voluntary motion. Martha, aged eighteen, who had eaten a small proportion, was attacked with similar symptoms.” By judicious treatment they all recovered. Upon investigation Mr. Sowerby determined the mushroom to have been a variety of the A. glutinosus of Curtis (Flora Londinensis) the same with Dr. Withering’s A. semi-globatus; and yet no notice of its deleterious properties is taken by either of these botanists.

A less fortunate case of poisoning by Fungi is related in the twentieth volume of the same journal by Mr. Parrott, surgeon of Mitcham, of which the following is a sketch. The subject of the history was a family of six persons, viz. William Attwood, Ætat. 45; Eliza, his wife, 38; and their daughters, Mary, Æt. 14; Hannah, 11; Sarah, 7; Eliza, 5. They all ate stewed champignons, at one o’clock, on Monday the 10th of October, which stew was made in an iron vessel, and consisted of the articles already mentioned with the addition of butter and flour, pepper, salt, and water only; and each of the parties (Hannah excepted) was supposed to have eaten more than half a pint. Within ten minutes after they had eaten their meal, they felt their spirits exhilarated, and the eldest daughter said to her mother “how funny you look.” All the parties continued cheerful till about six o’clock, when having taken their tea, they were attacked with stupor, which was soon succeeded, by severe pains in the bowels, accompanied with violent vomiting, and copious purging, which continued till the following afternoon, when the parents became alarmed and sent for the surgeon. The treatment which was pursued appears to have been, in every respect, judicious, and Mary had so far recovered on the following day (Wednesday) that she walked into the village about a quarter of a mile from home; in the evening, however, the symptoms returned; on Thursday evening she became convulsed, and died on Friday morning at two o’clock. Eliza did not complain much of her sufferings, but became convulsed at the same time as her sister, and died half an hour after her. Sarah never complained of pain in the head, but was continually suffering under extreme pain in the bowels, which was aggravated by pressure, but no tension existed; she died on Saturday morning, in the same convulsed state as her sisters. A dog which had partaken of the stew died on the Wednesday night, apparently in great agony. The father recovered, the mother, who was two months advanced in pregnancy, miscarried, but ultimately became convalescent. Mr. Wheeler, of St. Bartholomew’s hospital, a gentleman who has been long known to the profession as an eminent botanist, no sooner heard of the event than he repaired to the spot where the mushrooms had been gathered, when he immediately recognised the Agaricus semi-globatus, which had nearly proved fatal in the instance related by Mr. E. Brande, and which, upon being shewn to the father, he instantly pronounced to be similar to those, of which the family had so unfortunately eaten.

In the above case of the family of Attwood, the body of Mary was examined, but no morbid appearance whatever could be discovered. In collecting the different phenomena exhibited in other recorded cases, they may be reduced to the following: “violet coloured spots over the integuments; abdomen extremely bulky; the tunica conjunctiva of the eye as if it were injected; the pupil contracted; stomach and intestines inflamed, and scattered over with gangrenous spots; and, in some cases, they have exhibited very considerable contractions, so much so as almost to obliterate the canal. In no case have any remains of the mushroom been found. The lungs have been observed inflamed, and gorged with black blood.”

There cannot, however, be any doubt but that the different species of poisonous agarics act very differently.

Antidotes.

In all cases, the first object is to evacuate the offensive matter by emetics. After which, stimulants, especially ammonia, will be found highly serviceable.

Alcohol.

In treating of the action of this substance upon the human body, it may be considered as a slow, or quick poison; as one which, according to the circumstances of its administration, may either implant the seeds of disease and death, by an insidious, and scarcely perceptible operation, or extinguish the principle of animation in the space of a few hours.

Its effects as an accumulative^[470] poison are principally interesting to the physician in their relations to therapeutics, although their history may perhaps suggest some few points of interest to the founders of medical police.

We shall, therefore, observe, with regard to the habitual use of fermented liquors, that the bodily evils which arise from the custom rather depend upon the quality, or, in other words, the state of combination in which the alcohol exists in such liquors, than on the absolute quantity of the libation, or the frequency with which it is repeated. Daily experience convinces us that the same quantity of alcohol applied to the stomach under the form of wine, and in a state of mixture with water, will produce very different effects upon the living body, as well with reference to the immediate symptoms, as to the remote consequences of the potation; it has, for instance, been clearly demonstrated that port, madeira, and sherry, contain from one-fourth to one-fifth their bulk of alcohol;^[471] so that a person who takes a bottle of either of these wines, will thus take nearly half a pint of pure alcohol, which is equivalent to a pint of brandy! The remote consequences too of alcohol in these different states, are as striking and distinct as their immediate effects. It is well known that diseases of the liver are the most common, and the most formidable of those produced by the use of ardent spirits; it is equally certain that no such disorders follow the intemperate use of wine that is perfectly pure; let it be remembered that the greater proportion of that which is drunk in this country contains uncombined brandy, purposely added to meet the demand of the British market; and Dr. MacCulloch thinks that it is to the unwitting and concealed consumption of this uncombined spirit, that we ought to attribute the prevalence of those hepatic affections which are comparatively little known to our continental neighbours. But although wine, in a state of purity, may be thus fairly excluded from the general obloquy which attaches to spirituous potations, it must not be regarded as entirely free from imputation. “The effects of wine,” says Rush “like those of tyranny in a well formed government, are first felt in the extremities; while spirits, like a bold invader, seize at once upon the vitals of the constitution.” And even with respect to ardent spirits, although they can only be regarded as diluted alcohol, still each species appears to possess a peculiarity of operation; owing, no doubt, to the modifying influence of the other elements of the liquid; thus brandy^[472] is said to be cordial and stomachic; rum more heating and sudorific; gin and whiskey, diuretic; and arrack, styptic, heating, and narcotic. It seems also that a modified effect is produced by the addition of various other substances, such as sugar and acids; which latter bodies, besides their anti-narcotic powers, appear to act by favouring a more perfect combination and mutual penetration of the particles of spirit and water. The effects also which are produced by the habitual use of fermented liquors differ essentially according to the kind that is drunk; thus ale and porter, in consequence of the nutritive matter, and perhaps the invigorating bitter with which they are charged, and the comparatively small proportion of alcohol which they contain, dispose to plethora, which is sometimes terminated by apoplexy.^[473]

Symptoms of Poisoning by Alcohol.

The ordinary effects of an excessive dose of any spirituous liquor are too well known to require description; and generally pass off without the necessity of professional interference. In cases, however, where the draught has been very large, the person has suddenly fallen down in a state of complete insensibility, and has exhibited all the phenomena of apoplexy; or, in some instances, he has expired almost immediately. The insensibility of the patient may render it difficult for the practitioner to distinguish the immediate cause of the symptoms; although his history for the last few hours, and the spirituous odour of his breath, will generally announce the true nature of his situation. Mr. Brodie observes that there is a striking analogy between the symptoms arising from the ingestion of spirits, and those produced by injuries of the brain; concussion of the brain, which may be considered the slightest degree of injury, occasions a state of mind resembling intoxication; pressure on the brain, which is a more severe injury than concussion, produces loss of motion, insensibility, dilation of the pupils, laborious and stertorous respiration, and death.

We shall not enter into the history of the slow operation of repeated doses of spirit upon the human body; but limit our present inquiry to the modus operandi of this agent, as a quick and destructive poison.

Large draughts of liquids containing alcohol, would appear to destroy, at once, the functions of the brain, without occasioning that previous stage of excitement, which is produced by smaller quantities of spirit—whence coma and insensibility are the immediate consequences; and the nervous energy being no longer conveyed to the muscles of respiration, the breathing becomes laborious, and the patient dies, as he does in apoplexy, for want of those changes in the blood which are produced by the respiratory functions.^[474] In the greater number, however, of fatal cases of inebriety, life has been destroyed by circumstances purely accidental; such as improvident exposure to cold, as explained at page 59, or suffocation from an imperfect act of vomiting, during which a portion of the contents of the stomach are forced into the trachea, (see page 58,^[475].) It having then been clearly established that the brain is the organ principally affected by a large dose of alcohol, it remains to be explained in what manner, and through what medium such an effect is produced; upon this question we are inclined to concur with Mr. Brodie, and to consider that alcohol acts sympathetically on the brain by means of the nerves of the stomach; for it has been observed that animals which die under such circumstances, exhibit a decided inflammation of the stomach; and, in the next place, the effects produced by this agent are too instantaneous to admit the possibility of absorption, while repeated instances have shewn that vomiting will often restore the intoxicated individual to his senses. At the same time, we think it very probable that, upon some occasions, the alcohol passes into the current of the circulation, and is thus carried to remote organs. Dr. Cooke^[476] has related a case, on the authority of Sir A. Carlisle, of a person who was brought dead into the Westminster hospital, in consequence of having drunk a quart of gin for a wager, at a draught; and that upon examination, a considerable quantity of a limpid fluid was found within the lateral ventricles of the brain, distinctly impregnated with gin. We well remember this case, for it occurred during the period that the author of the present work held the situation of physician to that hospital. See Pharmacologia, vol. 1, p. 138.

Treatment of Persons in a State of Inebriety.

In the first instance we should endeavour to evacuate the stomach; for which purpose a brisk emetic of sulphate of zinc, or tartarised antimony may be administered. Blood should also be taken from the jugular vein, or temporal artery; more especially if there appear a considerable determination of blood to the head. The head should be also washed with cold water, or some evaporating lotion.

For reasons which we have already explained, the patient should be carefully preserved in a warm atmosphere; and his body should be placed in an easy reclining posture, and be disencumbered of all tight bandages. These precautions are of the utmost moment, for many of those cases of inebriety which stand recorded in our journals, have terminated fatally, for want of attention to them.

This extensive kingdom of Nature presents us with a variety of objects destructive to human life; their agency, however, is on many occasions involved in impenetrable obscurity, and we are not even able to discover whether their deleterious effects depend upon certain definite principles, or upon the combination of circumstances connected with the individuals upon whom they act; and which thus render many substances relatively poisonous, that are innocuous to the general mass of mankind. With regard to the chemical laws by which animal compounds are governed, and the principles upon which their analysis may be conducted, the same observations will apply as those with which we introduced the consideration of vegetable poisons.

Cl. IV. SEPTIC POISONS.

The Bites of Venomous Animals.

Of the whole class of serpents, which according to LinnÆus contains 132 species, Plenck assures us that only 24 are venomous. Of these, Europe has only 5, and England but 2; all of which are vipers, viz. Coluber Aspis; C. Chersea; C. Prester (black viper, peculiar to England); C. Illyricus (inhabits the mountains of Sclavonia); C. Berus, (the common viper of Germany, Spain, Italy, and England.)

The venom of the viper is contained in a bag situated on both sides of the head, beneath the muscle of the superior jaw; it is secreted from the blood by a gland which lies just behind the orbit of the eye; from which a duct proceeds to the above-mentioned bag; in the upper jaw are situated two moveable teeth, very sharp towards the point, and hollowed nearly throughout their length. When the animal intends to bite, he presses the bag by means of the muscle, the venom comes out, arrives at the base of the tooth, passes through the sheath which envelopes it, and enters into its cavity by a hole which is found at this base; then it flows along the hollow of the tooth, and issues into the wound by the opening which is near its end, for the point itself is solid and sharp, in order that it may better penetrate the flesh of its victim. If these fangs be removed, or their structure destroyed, the viper is necessarily rendered harmless; whence Galen has observed that the mountebanks used to stop these perforations of the teeth with some kind of paste, whenever they suffered the vipers to bite them before spectators.

Symptoms occasioned by the Bite of a Viper.

Acute pain in the wounded part, attended with almost immediate tumefaction; the part appears first red, and then livid; the local affection extends itself, and the surrounding skin becomes similarly affected. The pulse is small, frequent, and irregular; the respiration is disturbed; the patient complains of great debility, and faintness which often amounts to syncope; vomiting takes place; pain is felt in the umbilical region, and he becomes jaundiced; and, in fatal cases, the wound assumes a malignant character, and gangrene takes place.

In this country the affection is rarely mortal,^[477] although the circumstances of constitutional debility, unusual heat of season, and injudicious treatment, have in several instances led to a fatal issue.

Physiological action of the Poison of Vipers.

The result of numerous experiments justify us in referring this poison to the second division of our classification. The symptoms which it produces evidently depend on its absorption, and its passage into the circulation, when it exerts its peculiar action on the blood. It is somewhat singular that this poison should be perfectly inert when taken into the stomach; a fact, however, which appears to have been well known from the earliest periods; whence such wounds were commonly sucked^[478] with impunity; and we learn that when Cato marched the remains of Pompey’s army through Africa, he very wisely informed the soldiers, who, although dying from thirst, feared to drink the waters which contained serpents, that no evil could arise from such indulgence.^[479]

Among the insects of Britain some will be found to possess fluids highly stimulant, and sometimes, although rarely, occasioning death. These British insects, however, cannot be compared in virulence with the Furia Infernalis, Pulex Penetrans, the Scorpion, and the Tarantula; but their natural history is nevertheless interesting, and the instances of mischief arising from an application of their venom are not unimportant. Of the genus Vespa we have three species, each of which possesses the property of producing violent and painful inflammation, sometimes followed by considerable danger, where the injury has been inflicted on parts of great sensibility, and in irritable habits, viz. Vespa Crabro, the hornet; V. Vulgaris, common wasp; C. Coarctata, small wasp. Instances are recorded of the wasp, having been introduced into the mouth with fruit, and produced by its sting on the velum palati a sudden swelling which has so intercepted the respiration as to occasion suffocation.^[480] Of the Apis there are seven British species; the most remarkable of which are the Apis Rufa, or small field bee; A. Mellifica, the common hive bee; A. Terrestris, humble bee; and A. Subterranea, or great humble bee.

The sting of a single bee cannot be regarded as attended with danger, except in certain constitutions; but there are many instances of men and animals having suffered most terribly, and even fatally, by an attack of a swarm of these insects.

The supposed poison of the toad is a subject which we have already disposed of, under the literary history of poisons, page 139.

Putrescent Animal Matter.

A question has long since arisen, how far the ingestion of animal matter, in a state of putrefaction, is liable to affect the health? On the one hand it has been maintained that the custom of eating game, venison, and other species of animal food, in a state of incipient putrescence, has never been attended with any inconvenience; but appears, on the contrary, to afford a repast of easier digestion, than the flesh of recently killed animals. On the other hand, it has been asserted by FoderÉ,^[481] and corroborated by the testimony of others, that corrupted meat, fish, and eggs, are undoubted poisons; if, through inadvertence, necessity, or extreme hunger, they are taken in any quantity. The same distinguished writer relates that, during the siege of Mantua, several persons who were shut up in the town were seized with gangrene of the extremities, and scurvy, in consequence of having been driven to the alternative of eating the half putrid flesh of horses. In Crantz’s history of Greenland we read an account of the death of thirty-two persons, at a missionary station, called Kangek, shortly after a repast upon the putrid brains of a Walrus.

It would appear that under circumstances not hitherto understood, certain parts of animal bodies become poisonous; and the virus would not seem to be connected with any stage of putrefaction, nor with any previous disease in the animal. As far as our limited experience upon this subject will allow us to generalize, the brain and the viscera would appear to be particularly susceptible of such a change. Some curious and highly interesting observations have lately been published by Dr. Kerner, of Wurtemberg, respecting the probable existence of a species of animal poison not hitherto known. He informs us that the smoked sausages, which constitute so favourite a repast to the inhabitants of Wurtemberg, often cause fatal poisoning. The effects of the poison occasionally manifest themselves in the spring, generally in the month of April, in a degree more or less alarming. He states that out of seventy-six persons, who became sick from having eaten such sausages, thirty-seven died in a short time, and that several others remained ill for years. Upon these occasions it has been observed, that the most virulent sausages were made of liver. M. Cadet, of Paris, analysed all the meats, examined all the vessels in which they had been prepared; and inspected the matters vomited, or found in the stomach after death, without being able to trace the vestige of any known poison; nor was there the slightest evidence in these cases of malevolence or negligence. Similar accidents have occurred at different periods in Paris; upon which occasions, the police officers visited the pig dealers, and were perfectly assured that the animals had never been fed with unwholesome food; the use of poison for rats, with which these places abound, was interdicted, and every precaution taken. What then, asks M. Cadet, is this poison found in sausage meats—is it Prussic acid—is it a new matter? It is evidently not the effect of putrefaction, since it exists in meats perfectly well preserved. To the above queries of M. Cadet, the author of the present work begs to add one more—may not the skin enclosing the sausage meat be the part in which the poison resides? It is well known that the bodies of animals who die of various diseases, are capable of communicating fatal diseases to the human species; and experience has shewn that such animal poison is particularly energetic in those parts that are commonly called the offals, in which term are included the intestines; in the history of fish-poison, which will hereafter offer itself to our notice, we shall find numerous instances of dogs, cats, hogs, and birds, dying from eating these parts, while persons, who have partaken of the fish to which these offals belonged, remained uninjured. But to account for the deleterious change of which these parts appear to be occasionally susceptible, it does not appear necessary to suppose that the animal died in a state of disease. Captain Scoresby, in his “Account of the Arctic regions,”^[482] states that although the flesh of the bear is both agreeable and wholesome, the liver of that animal is poisonous; sailors who had inadvertently eaten it, were almost always sick afterwards, and some actually died; while in others the cuticle has peeled off their bodies. The ancients appear to have entertained a fear with regard to the wholesomeness of the viscera of certain animals, and of the fluids which they secrete. Pliny says that the gall of a horse was accounted poison; and, therefore, at the sacrifices of horses in Rome, it was unlawful for the Flamen (priest) to touch it. Mr. Brodie has lately favoured the author with the communication of a fact, which goes far to support the theory we have offered with respect to the possible source of poison in sausages. He states that he has twice met with evidence of the acrid and poisonous nature of “dog’s meat,” as sold in the streets of London, which manifested itself by producing ulcerations, of a peculiar character, on the hands, and swelling in the axillÆ, of the venders! May we venture to ask whether the prosecution of this inquiry might not possibly lead to some new and important conclusions respecting the origin of hydrophobia?

Where animals have died from disease, their flesh has undoubtedly produced affections by external contact, as well as by its ingestion. At the Somerset assizes in 1819, a case was tried, whose merits wholly turned upon the question now under discussion. A cow, having died of some disease, was thrown into the river Yeo, and several cattle that afterwards drank of the water died of a similar complaint. An action was accordingly brought against the owner of the cow for damages. The defendant, however, obtained a verdict, apparently from the evidence of a medical person, who asserted that animal matter in a state of putrefaction will not communicate contagion. But we must here beg to observe that this is quite another and distinct question; the merits of which we have already considered.^[483] The physiological question involved in the preceding case, is whether the carcase of an animal, whose fluids have been depraved by antecedent disease, is capable, or not, of producing morbid and fatal affections in the living animals with which it may come in contact? The facts collected by MM. Enaux and Chaussier, in their work entitled “Methode de traiter les Morsures des Animaux enragÉs,” prove in a very satisfactory manner that the Anthrax, or Malignant Pustule, has for its cause a septic virus engendered in diseased animals, and transmitted to man.^[484] The following are amongst the more striking examples cited from these authors by Orfila. “A shepherd bled one of his sheep, which had just died suddenly; he carried it home on his shoulders; but the blood penetrated his shirt, and was rubbed upon his loins. Two days after, a malignant pustule appeared upon this spot.”

“A boy employed in skinning an ox which had been killed at an inn at Gatinais, because it had been sick, put the knife into his mouth. Shortly after which the tongue swelled; he experienced a tightness of the chest; the whole body was covered with pustules, and he died on the fourth day, in a state of general gangrene. The inn-keeper, who was pricked in the middle of the hand by a bone of the same animal, suffered great pain; gangrene seized the arm, and he expired on the seventh day. The servant girl received on her right cheek a few drops of the blood of the same ox, which produced inflammation, followed by gangrene.”

In this country, a case has occurred highly illustrative of the present subject. A pupil of the veterinary college accidentally inoculated himself, during his dissection, with the matter of a glandered horse; the student soon experienced the usual symptoms of a septic poison; abscesses formed in various parts of his body, and he sank under the disease. Upon inoculating a healthy horse with some of the matter from the abscesses, the animal was attacked with the glanders.

This subject necessarily leads us to the notice of those effects which are frequently produced in the anatomist, by a puncture made during dissection. From the history of those cases which stand recorded, it does not appear that the poisonous effects are either connected with the putrefactive state of the body under dissection, or with the peculiar disease of which it died; but rather with the depraved state of the operator’s health; for it has been repeatedly remarked that those students who enjoy high health universally escape the evil, however repeatedly they may have been exposed to its causes.

The number and validity of recorded cases establish the fact, beyond dispute, that certain fish, especially the muscle, (Mytilus Edulis) and others of the shell tribe, have occasionally proved fatal to those who have eaten them; but it has been doubted whether such effects have arisen from a specific poison, or from the peculiar state of the stomach,^[485] or idiosyncrasy of constitution, in the persons affected. In other words, ought we to consider the fish, so circumstanced, as an absolute or relative poison? Each of these theories has met with its advocates, and many striking facts and illustrations have been adduced in their support. The weight of authority, however, as well as of argument, strongly inclines in favour of the existence of a specific virus, generated under circumstances which we are at present unable to appreciate. At the same time, it would be vain to deny, that certain fishes are more obnoxious to the stomach of one individual than to that of another; there are, for instance, those persons who are disordered whenever they eat a muscle; others who are incapable of taking an oyster without considerable disturbance of the digestive functions. This is obviously Idiosyncrasy, and must not be confounded with those cases where a number of persons have been simultaneously affected from a particular food, which, on all former occasions, had been eaten by the same individuals with perfect security. We must, therefore, at the very outset of our inquiry, admit the occasional action of these articles of diet as relative poisons; although it is evident to demonstration, that an absolute virus is generated in particular fishes, by the operation of causes hitherto unknown.

As a subject, highly important in its relations to maritime oeconomy, the history of fish-poison constitutes an interesting branch of naval hygiene; instructions, therefore, for its investigation, ought always to be given to the naturalists and chemists who may be appointed to attend voyages of discovery. The notice of the scientific men who accompanied Peyrouse was officially directed to this important object; but the unhappy fate of that celebrated adventurer rendered the commission fruitless. The obscurity which attends this branch of toxicology has in many cases occasioned a corresponding degree of credulity; and sailors, as well as others, entertain an unfounded prejudice against various fish, that are not only innocuous, but even useful as articles of food. It would, however, appear that those which are harmless in one latitude may prove poisonous in another; it may be stated generally, that fish are more deleterious within the tropics, than in other seas. In torrid regions the softest kinds are the most susceptible of that change which renders them poisonous, and hence the policy of the Hebrew legislator becomes apparent; “whatsoever has no fins nor scales in the waters, that shall be an abomination unto you.” Levit. c. xi, v. 12, and Deut. cxiv, v. 9, 10.

The most complete history of this intricate subject, and of the dissertations to which it has given rise, is to be found in the Edinburgh Medical and Surgical Journal,^[486] by Dr. Chisholm, who has brought together, and cited a great number of authorities, biblical and classical, foreign and domestic, for its illustration. An interesting paper is also published on the same subject in the Medical Repository,^[487] by Dr. Burrows. To the above sources we must beg to refer the reader who is desirous of farther information than can be afforded him by the present work.

Symptoms of Fish-poisoning.

Nausea; thirst; tormina of the bowels; vomiting; an eruption on the skin, resembling the nettle-rash; tumefaction of the face; head-ache; difficult respiration; distention of the abdomen; sometimes cholera morbus; vertigo; delirium; cold sweats; convulsions; death. Such is the train of symptoms, liable of course, to variation in the order of succession, which are produced by the ingestion of fish-poison, as occasionally existing in salmon, herrings, eels, mackarel, many of the testaceous and most of the crustaceous fish of this country; and in a great number of fish^[488] inhabiting the tropical seas.

The species of fish, from which deleterious effects have more commonly arisen in this country, are the Mytilus Edulis, or muscle. Dr. Burrows has given us an account of two cases of death from eating these fish, which occurred at Gravesend, under the care of Mr. Rogers, surgeon of that place, upon whose authority the statement is drawn up.^[489] The subjects of the history were two youths of the ages of nine and fourteen, who had each eaten about a dozen of small muscles, which they had picked from the side of a fishing smack, in a dead and tainted state. In the Gazette de SantÉ,^[490] and in the works of FodÉrÉ,^[491] and Behren,^[492] similar cases are recorded. Vancouver,^[493] in his voyage to the coast of America, relates that several of his men were ill from eating some muscles which they had collected and roasted for breakfast; in an hour after which they complained of numbness of the face and extremities, sickness, and giddiness. Three were more affected than the others, and one of them died.

Origin of Fish-poison.

If we admit that the symptoms which are occasionally produced by the ingestion of certain fish, depend upon the presence of poison, we have next to inquire into its nature and origin. Dr. Burrows considers that all the opinions which have been advanced upon this subject may, for the greater perspicuity and facility of discussion, be arranged under seven heads, viz. does the poison exist—1. In the skin?—2. In the stomach and intestinal canal?—3. In the liver or gall bladder?—4. In the entire substance of the fish?—5. In the food of fishes?—6. Is it a morbid change in the system of the fish?—7. Is it a poison, sui generis?

Upon these several questions Dr. Burrows has offered some observations. There do not appear to be any facts which can induce us to consider that the poison resides only in the skin.

Experience has shewn that the virus is particularly energetic in the viscera, commonly called the offals; and yet there are no grounds for concluding that it exclusively belongs to these parts. Captain Cook, and Messrs. Forster were poisoned by eating a piece of the liver only of a species of tetrodon; yet they who ate of its substance were also poisoned.

An opinion has long prevailed that the poisonous principle is derived from the substances upon which the fish feeds; and that of muscles, in particular, from copper; this latter hypothesis has received the sanction of Dr. Chisholm. We however agree with Dr. Burrows in considering that it has neither the support of observation or analogy. Dr. Beune has supposed that the acrid principle is no other than the spawn of the stella marina, an insect which very commonly lodges in the muscle. It seems, however, more probable that it is a product of decomposition, but which requires the concurrence of certain circumstances for its developement.

Before we conclude the history of septic poisons, there appears to be a species of death, particularly noticed by Dr. Gordon Smith,^[494] which merits our attention, as having some relation to this class of agents—the fact of persons having been “eaten to death by maggots!” Such a death has been assigned to Sylla, by Plutarch; and to Antiochus Epiphanes, by Josephus, and the writer of the book of Maccabees. The fate of Herod is ascertained by Scripture. In modern history we have similar instances in Charles IX of France, and Philip II of Spain.

Numerous cases are recorded, in different medical works,^[495] of the generation of maggots, i. e. the larvÆ of different species of fly, not only in external sores and excoriations, but in the internal cavities of the human body. Dr. Lempriere^[496] has related the case of an officer’s lady, who had gone through an acute fever, but in whom these maggots were produced, which burrowed, and found their way by the nose through the os cribriforme, into the cavity of the cranium, and afterwards into the brain itself, to which she owed her death. But of all the cases of this kind, that related by Dr. Gordon Smith is of the most revolting kind. “In the month of July 1809, a man was found near Finglas, in Ireland, lying under the wall of a lime-kiln, at an early hour in the evening, with his face on the ground, apparently dead. On turning him on his back to ascertain the real state of the case, it was discovered that he was yet alive, but under the most appalling circumstances. On removing his coat, the whole surface of his body appeared to be a moving mass of worms. His face was considerably injured as if from a fall, or bruises; his eyes were dissolved, and their cavities, as well as those of the ears, nose, and mouth, were filled with a white living mass, from which such innumerable quantities of maggots were continually pouring out, that the skull seemed to be filled with nothing else. After some time he recovered strength enough to walk, and regained recollection and voice sufficient to tell who he was, where he lived, and how he had been brought into that situation. It appeared that he was returning home upon a car the evening before; having drank to excess, he fell off, and remained in a state of insensibility until he was discovered. He could neither account for the wounds in his head, nor for his being so far from the road; but it appeared probable that he had received the contusion from the fall, and had insensibly crawled to the place where he lay. It was conjectured that the state of the atmosphere, as to humidity and temperature, had brought on a solution of the solids in the bruised parts, already disposed to putrescency, and now in close contact with the moist earth. In these, the eggs of innumerable insects being deposited, their generation proceeded with rapidity under circumstances so favourable. Every attention was paid to the unfortunate individual; he was removed to shelter, the parts were washed with spirits and vinegar, and the loathsome objects removed, as far as was possible. Cordials were poured down his throat, but he swallowed with difficulty; and in a very short time spasms took place which prevented him from swallowing altogether. The putrescence advanced; in a short time he became insensible; and about noon the following day he died, in a state of total putrisolution.”

Under this division we include all those deleterious substances which can be administered through the medium of the atmosphere.

Those gases, the respiration of which occasions death by the negative operation of excluding oxygen, are not ranked under the class of poisons, for the history of such bodies involves physiological views peculiar to themselves, and belongs more correctly to the subject of suffocation, under which head it has already met with full consideration, vol. 2, p. 48.

AËrial poisons are of very undefined extent, and their history is involved in considerable obscurity. Every poison, capable of volatilization, may be admitted into the division; and even those substances which are generally regarded as fixed, may be mechanically suspended in the air, and thus produce their effects on the living system, through the medium of the lungs, stomach, or nerves. In the present state of our knowledge, we have, perhaps, only an imperfect idea of the distinction between a fixed and a volatile body. A very interesting paper on this subject was read before the Royal Academy of Berlin, by Professor Hermbstaed,^[497] in which he observes that, generally speaking, we might consider all bodies as volatile, as it is most probable that, could we produce a sufficient degree of heat, no substance could resist it. The professor also states that many bodies, hitherto considered as fixed, are actually volatilized at the temperature of boiling water; such he found to be lime, baryta, strontia, and potass. We apprehend, however, that the professor has, in these instances, mistaken a phenomenon for volatility, which it is highly important to distinguish from it, viz. the elevation of a certain portion of a fixed body, by the carrying power of a vapour; thus, fixed oil may, in a minute proportion, be carried up with the steam of water. Certain bodies, however, which have been long considered as perfectly fixed at the ordinary temperature of the atmosphere, have been lately discovered to undergo a slow and almost imperceptible evaporation under such circumstances; and the discovery has led to a very satisfactory solution of several problems which were previously unintelligible. We shall adduce a striking exemplification of this truth, under the consideration of mercurial vapours.

The substances, included under the head of AËrial poisons, may be conveniently arranged in two orders, viz.

I. Those, whose particles exist mechanically suspended in the atmosphere.

II. Those, which are presented to us in a vaporous or gaseous form.

Of the first division the various arts will furnish ample illustration, as for instance the occupations of the colour-maker, plasterer, cotton-spinner, dry-grinder,^[498] stone-cutter, hatter, furrier, miller, &c. &c. In all of which a subtle matter is given off, which becoming mechanically suspended in the air, penetrates the structure of the pulmonary organs, and excites disease, and even death.^[499] In illustration of the second division, we have the trades of water-gilders, acid manufacturers, night-men, bleachers, and various others, many of which have been already noticed under the medical and chemical consideration of nuisances, vol. I, p. 330.

In the present chapter we cannot attempt an enumeration of every substance which may act as an aËrial poison; we shall confine our attention to the history of a few bodies which are calculated to afford general elucidation, and are likely to become objects of forensic interest.

Mercurial Vapours.

It is not the least interesting fact in the history of aËrial poisons, that substances, which are found to be extremely slow in their action, or even quite inert, when administered in their solid or liquid state, exert a very rapid and energetic operation when they are presented to the human body in the attenuated form of vapour. This fact is well illustrated by the subtlety and activity of metallic mercury in the state of vapour; a substance which, according to the highest authorities, is quite inactive when introduced in its grosser form into the stomach. It is thus that the workmen employed in gilding, silvering looking-glasses, constructing barometers, &c. experience such dreadful effects; that such effects arise from the metal in a state of vapour, and not, as some have supposed, from the oxide,^[500] is a fact capable of demonstration, for the artists at Birmingham affix an apparatus in their chimneys as a system of economy, in order to collect the mercury, which is always found in its metallic state.^[501] From the late interesting experiments of Mr. Faraday,^[502] it appears that mercury rises in vapour at the ordinary temperature of the atmosphere; the knowledge of which fact will afford a very satisfactory explanation of several phenomena, which were previously unintelligible. Dr. Hermbstaed, in the memoir, above mentioned, “on the volatility of substances hitherto considered as fixed bodies,” relates the following curious fact with regard to the volatility of mercury. “At the Royal Manufactory of looking-glasses in Berlin, during a severe winter, the artificers who worked in a room, which had originally served for the process of silvering the glasses, lighted a fire, and thus heated the apartment to between 86° and 96° Fah. In a few days the whole of them were, to their great surprise, affected by a strong salivation, as there was no trace of mercury in, or near the room. They consulted on the subject, and suspecting the real cause of the event, had the flooring of the room taken up, when about 40 lbs of the metal were found spread about in different parts, where it had fallen at various times during the operation of silvering, which had been executed in that room before.” With such facts before us, we shall no longer be unable to explain the effects which were produced on board his majesty’s ship Triumph, off Cadiz, in April 1809, by the bursting of leathern bags containing quicksilver, and the consequent dispersion of not less than three tons of the metal through the vessel. The interest excited by this case has been very great, and as the facts, involved in its history, are of high medical importance, we were induced to apply for permission to search the journals of the ship; and, through the kindness of Dr. Burnett, one of his majesty’s commissioners for victualling the navy, and the assistance of Mr. Plowman, who held the situation of surgeon to the Triumph, we have been enabled to obtain a correct and detailed history of the event. Previous to the circumstances we are about to describe, “the ship’s company had been tolerably healthy, when unfortunately a quantity of quicksilver was received on board, and diffused over the ship in consequence of the bursting of the leathern bags, in which it had been enclosed; when its effects were soon displayed upon the crew, by occasioning ptyalism, partial paralysis, affections of the bowels; so that in three weeks, no less than two hundred men were in a state of salivation. In consequence of which two transports were taken up as hospital ships, in which the slighter cases soon recovered; but as many fresh cases occurred daily, Vice-Admiral Pickmore ordered a survey on the ship, and ship’s company, by the surgeons of the squadron, on the third of May, who reported the necessity of sending the ship into port, in order to clear her hold, change part of her provisions, into which the quicksilver had insinuated itself, and to purify her by means of ablution. This was accordingly done; but on stowing the hold afresh, every man so employed, as well as those engaged in the steward’s room, were attacked with ptyalism. Fresh cases happened daily, until they took their departure from Cadiz on the 13th of June; after which but few occurred, which was attributed by the surgeon to the coldness of the weather, the fresh breezes from the north-east, from the men having been kept constantly on deck, and not allowed to sleep on the orlop, and from not suffering those affected with ptyalism to lie on the lower deck; as well as from the constant attention paid in the ventilation of the ship by means of wind-sails. But, notwithstanding all these precautions, the ship had not been more than ten days at sea, when many of the men became worse, and it was found necessary to send twenty-four seamen on board the Goshawk, and two transports. On the arrival of the Triumph in Cawsand Bay, on the 5th of July, there did not remain one case of ptyalism on their list. During this extraordinary visitation two men died from excessive ptyalism, one of them at Cadiz, having previously lost his teeth, and both cheeks at the time of his decease being in a state of sphacelation; the other, who died at Gibraltar, had lost the whole of his teeth, two-thirds of his tongue, and, at the time of his death, the lower lip was in a state of gangrene. To the interesting facts above related, Mr. Plowman adds, that the interior of the ship was covered with a black powder, and that the copper bolts displayed the mercurial influence. The mercurial vapours proved fatal to the living stock on board, for nearly all the poultry, sheep, pigs, mice,^[503] goats, cats, a dog, and even a canary bird, died from its influence.”

Sulphuretted Hydrogen Gas.

This gas is transparent and colourless; it has the property of inflammability, and when set on fire in the open air, burns with a bluish flame, and deposits a certain portion of sulphur. It is distinguished by an excessively foetid smell, which has been aptly compared to that of rotten eggs. Its habitudes with other gases are interesting and important; by admixture with chlorine, it immediately undergoes decomposition, yielding its hydrogen, so as to form hydro-chloric acid (muriatic acid), and consequently depositing its sulphur; with ammoniacal gas it combines, and forms an hydro-sulphuret of ammonia; when mingled with sulphurous acid gas, the hydrogen of the former combines with the oxygen of the latter, and the sulphur of both is precipitated; when passed over ignited charcoal it is converted into carburetted hydrogen gas, and sulphur is deposited.

It is soluble in water, and the solution precipitates the different metals from their saline solutions, in the form of sulphurets; a property which at once distinguishes this gas from every other.

It has been long considered a very energetic poison, and it would, at the same time, appear to be a very insidious one; for sensibility is quickly destroyed by it, without any previous suffering. We are acquainted with a chemist who was suddenly deprived of sense, as he stood over a pneumatic trough, in which he was collecting the gas. It would seem to act upon the nervous system through the medium of the blood, in which it is extremely soluble. It constitutes the particular gas of privies, and is the immediate cause of those accidents which we have already described in a former part of this work, vol. 1, page 100; since the printing of which we have heard of the death of four persons from emptying a privy at Brompton. This gas will be sometimes developed during the imperfect combustion of wet coals^[504]; and it was probably owing to its presence, or to that of carburetted hydrogen, that the accident arose which is recorded by Mr. Sutleffe in the Medical Repository. “He was hastily summoned to a neighbouring family at bed-time, where he found a female domestic labouring under a shrill, laborious inspiration; she had taken up from a good kitchen fire, a panful of live coals, from which a sudden suffocating blast seized her.”

This gas is developed by several chemical processes. We have just stated that if, during the burning of charcoal, moisture be present, it is evolved in abundance. It appears to be particularly fatal to animal life. Dr. Beddoes made many experiments upon the subject, from which it would seem to destroy life by rendering the muscular fibre inirritable without producing any previous excitement. In order to decide this question, Sir Humphry Davy^[505] ventured to take three inspirations of the gas produced from the decomposition of water by charcoal. “The first inspiration produced a sort of numbness and loss of feeling in the chest, and about the pectoral muscles; after the second,” says he, “I lost all power of perceiving external things, and had no distinct sensation, except a terrible oppression on the chest; during the third expiration, this feeling disappeared; I seemed sinking into annihilation, and had just power enough to drop the mouth-piece from my unclosed lips. There is every reason to believe, that if I had taken four or five inspirations, instead of three, they would have destroyed life immediately, without producing any painful sensation.”

Chlorine—Oxy-muriatic Acid Gas.

This gas, which is now considered as an elementary body, has received from Sir Humphry Davy the name of chlorine, from the green colour which characterises it. Its odour is so penetrating and insupportable that it is impossible to respire it, even when considerably diluted with atmospheric air, and yet it will support combustion. It discharges vegetable colours, whence it forms the basis of various bleaching preparations. According to the experiments^[506] of M. Nysten, this gas is not absorbed when respired pure, but appears to act only by irritating the bronchiÆ locally; and so energetic is its action, that the animal dies before there is sufficient time for asphyxia to take place from the circulation of black blood. When it is respired in a dilute form, it produces a severe cough, and, according to Fourcroy, it occasions a phlegmonic inflammation of the bronchial membranes. The death of the ingenious and indefatigable Pelletier was occasioned by his accidentally inhaling a proportion of this gas; a consumption was the consequence, which in a short time proved fatal. In the London Medical and Physical Journal for November, 1821, a case of a person is recorded who was poisoned by bleaching liquor.

Sulphurous Acid Gas.

The gas is generated by the combustion of sulphur. It is colourless; has a pungent smell, resembling that of burning sulphur, and is very soluble in water. It would appear to destroy life by a peculiar action on the blood.