ON THE INTRODUCTION OF VITIATED FLUIDS INTO THE BLOOD; ITS CONSEQUENCES, AND TREATMENT, WITH CASES.

VIII. The experiments cited in the first part of this essay, illustrate the power possessed by the blood of preventing certain foreign substances from circulating with it. They shew that pus, in particular, has a tendency to coagulate the blood; and that by this means, when introduced into the vessels, its progress is arrested in some part of the circulating system. This fact, which, taken by itself, might appear of little consequence, assumes considerable importance when considered as one of the inherent properties of the blood, at all times ready, under favourable circumstances, to be called into action in the living body. The conditions under which pus will determine the coagulation of the blood, and those under which it will circulate in the living vessels, require to be accurately ascertained, before we can rightly interpret the discordant evidence which we at present have upon this point.

Dr. SÉdillot,[29] in a work recently published, mentions, that a great number of cases are met with, in which pus is poured into the general circulation without meeting with any obstruction, and states that, in such instances, he can detect the globules of pus in different parts of the circulating system. He even affirms that he can recognise a disease caused by purulent infection, by examining, under a microscope, a portion of the blood abstracted from the body.

M. Dance, and, since his time, equally accurate observers, have, on the other hand, failed to detect the characters of pus in the blood, even when that fluid had been injected into the veins of living animals. The results of these different observations may perhaps be reconciled, by considering the influence exercised upon the globules of pus by the blood, before its coagulating power has been impaired. This subject appears not to have hitherto occupied the attention of pathologists.

In all the cases quoted by Dr. SÉdillot, in which he detected the globules of pus in the blood, the patients died of the disease; but in the researches instituted by M. Dance and others, the experiments were made upon animals in perfect health. In the latter, the pus cannot enter the circulation, as has already been shewn, or can only do so after the blood has partially or entirely coagulated round it, and the coagulum has subsequently become broken up.

In the act of coagulation under these circumstances, the appearances of the globules of pus are changed,—these being perhaps mechanically compressed by the contraction of the fibrine,—so that the most experienced eye can no longer recognise them.

Pus, mixed with healthy recently drawn blood, out of the body, will entirely lose its characters in this way; and as the coagulation, is by no means retarded in the living vessels, we may, without fear of contradiction, affirm, that globules of pus cannot be detected when introduced into the vessels in small quantities, and mixed with healthy blood.

In cases where, from long-continued disease and the repeated introduction of vitiated fluids into the circulation, the blood has lost its power, there appears no reason to doubt the correctness of Dr. SÉdillot's observations; and it is probable that pus-globules may then circulate with those of the blood.

In experiments upon animals, it has always been found that the power of the constitution, in resisting the effects of the injection of pus into the veins, was much greater at the first than at any subsequent operation. This circumstance would appear to associate itself directly with the observations now made, and to afford another illustration of the power of healthy blood in resisting the entrance of some foreign matters into the system.

From the consideration of these facts, and of the experiments previously recorded, it becomes evident, that the introduction of pus into the system through an injured or inflamed vein, can rarely be the first step towards purulent infection of the system. Some change must previously have passed in the blood, by which its coagulating power is impaired, or some unusual mechanical means must have been employed, before the pus can find its way in the course of the circulation. The contradictory statements which have been made by those who have injected pus into the veins, may thus be reconciled, by taking into account the power exercised by the blood in the experiments which have been made. There can be little doubt that, while, in some instances, a portion of the pus has been forced into the general circulation, in the great majority of cases it has been detained in the vein into which it was first introduced, and has never become part of the circulating fluid. We accordingly find some experimenters recording the secondary diseases which they observed, while in other hands these appearances were not produced.

Dr. SÉdillot[30] has attempted to prove that the globules, or solid parts of pus, must be introduced into the system, in order to produce well-marked indications of purulent infection. But this hypothesis would not only appear to be at variance with the oft-repeated experiments of MM. Gaspard and Cruveilhier, in which similar effects were produced by the injection of mercury and of putrid fluids, but would also leave unexplained the mode of the introduction of these globules, where there is evidence that the disease has been communicated through the lymphatic system. The changes which all substances undergo in their passage through the absorbent glands, would at once forbid the idea that globules of pus could be thus introduced unchanged into the circulation; and yet we have direct evidence (Case xxix) that irritating fluids are conveyed in this way into the system, and lead to the formation of secondary abscesses.

Another class of cases, in which there would be difficulty in admitting the doctrine of the introduction of pus in substance into the circulation, presents itself, where, in the primary affections (as in Case VI), no evidence can be obtained of the original lesion having suppurated. The fluids effused in such cases may be serum, lymph, or blood, mixed in different proportions; and yet the constitutional symptoms will be exactly similar to those which follow the formation of pus in other instances. There may exist, both in the primary and in the secondary affection, every intermediate gradation between the healthy secretion of a part, and the formation of pure pus, or pus mixed with blood or lymph, without any of the essential characters of the disease being absent. An inflamed bursa, or a punctured wound, without the formation of pus, (Cases iv and v), may give rise to symptoms as severe, and consequences as fatal, as any that arise from the direct introduction of pus into the system. The secondary affections, in such cases, may run their course and prove as speedily fatal, as where well-formed purulent deposits have taken place. The most severe constitutional symptoms will sometimes be followed by the effusion of bloody fluid only, in one of the serous cavities (Case xxx). It would be unphilosophical, even were it practicable, to refer such cases to a different disease, merely because the accidental circumstance of the formation of pus is wanting. The origin of the affection in such instances may be as well-marked, the poison can often be traced as distinctly into the system, and the secondary disease may be as clearly connected with the primary, as in any case where pus has been originally formed. In some cases again, the constitutional symptoms which accompany, or are followed by, effusions into distant parts of the body, begin before sufficient time has elapsed to allow the supposition that pus can have been fully formed at the original seat of injury. Such instances occasionally, although rarely, present themselves in extensive burns and scalds, occurring in enfeebled habits, and after amputation of the limbs in scrofulous children.

In nearly all cases, when the origin of the constitutional disease cannot be traced to the introduction of diseased fluid into the system through an open vein, it will be found that the part primarily injured has wanted the degree of vigour, requisite to establish and maintain healthy adhesive inflammation.

Upon another occasion,[31] I have endeavoured to show that, where lymph is effused around a poisoned wound, the virus will find its way less easily along the absorbent vessels, than when no such effusion has taken place; and that when, in such a wound, the effusion of lymph is checked or prevented, as by the administration of mercury, a larger proportion of cases will indicate an affection of the lymphatic system, than when the natural process has not been interfered with. There can be little doubt, that the same principle may be observed with regard to ordinary wounds. The number of cases in which the absorbents inflame, will be in inverse proportion to the number of those in which the original wounds are circumscribed by healthy adhesive inflammation. In Case xxvii, it is mentioned, that the surface of a muscle, implicated in the original lesion, was as cleanly dissected as if done with a scalpel, thus showing the total absence of any surrounding effusion of lymph. The absence of, or defect in, the process of adhesion may thus be associated with inflammation of the absorbents, as the want of "union by first intention" has been shown to be connected with inflammation of the veins (Section ii.)

The minuteness of the absorbent vessels, and the changes which their contents undergo in their glands, prevent any unhealthy fluids from being as readily recognised in them as in the veins. But when the progress of inflammation can be traced along these vessels from a wound, towards the centre of the circulation, marked, as it often is, at intervals, by the formation of abscesses, we cannot doubt that an irritating fluid has found its way along their canals: and when the constitutional symptoms, which arise at the same time, terminate in the formation of purulent deposits (as in Case xxix), we cannot but admit that the absorbent vessels are the direct means by which, in such cases, diseased secretions are poured into the blood, and the system becomes infected. It would, therefore, appear that there are two principal conditions, under which local disease may produce a general infection of the system by the direct introduction of vitiated fluids into the blood. The first of these is connected with defective union in injured veins; the second is associated with want of healthy adhesion in inflamed lymphatics.

The period of invasion of the attack differs in some degree in the different classes of cases, but it is generally marked with great precision: even when apparent recovery has been followed by a second attack, the occurrence has in each instance been accurately noted by the sudden appearance of constitutional symptoms (see Case xxxvii).

When one of the large veins has been originally affected, the period which elapses before symptoms of infection of the system manifest themselves, is comparatively short (Case i). In cases occurring after child-birth, it is usually longer, extending to the end of the second week. After surgical operations or accidents involving some portion of bone, the access of the disease will be marked by a rigor during the third or fourth week; and finally, when the absorbent system is primarily affected, the period of the occurrence of the constitutional symptoms may be much farther removed from that of the original injury (if any such existed), and is by no means so accurately defined.

At the time of the occurrence of the general disturbance of the system, the local injury or wound will generally put on an unhealthy appearance. The skin in the immediate neighbourhood will sometimes assume a dull brownish-red appearance, which will gradually fade into the colour of the surrounding parts. This symptom will usually commence near the termination of the vessels, which are derived from the same trunk as those which supply the injured part. When the original injury is complicated with a wound upon the surface of the body, it will usually become dry and glazed, and the blush upon the skin will commence in its neighbourhood, or a short distance from it, and will usually extend towards the centre of the circulation, without presenting any very defined margin: occasionally it will extend, in the form of erratic erysipelas, over a large part of the body.[32]

IX. The commencement of constitutional disease, after direct infection of the blood, is marked by a sudden change in the manner and appearance of the patient; a severe rigor is usually the most prominent symptom, and is followed by much febrile excitement, or by extreme depression; a very peculiar heat of skin (Case xxii) will sometimes be present, while, at other times, the surface will be covered by a profuse clammy perspiration. The rigor may be repeated at irregular intervals, but occasionally it will recur about the same hour for three or four days in succession (Case xxxvii); and in a few instances it will not be observed at all.

Great depression frequently accompanies even the first stages of this disease, indicated by a want of tone in the pulse, by an extremely listless manner, and sometimes by a tendency to syncope (Case i). The countenance becomes anxious, the tongue dry and brown in the centre, and red at the edges, or, in other instances, it presents a coating of a pasty yellowish-white colour; a dusky yellow hue frequently pervades the skin, and sometimes the conjunctivÆ of the eyes. This may or may not depend upon an accompanying affection of the liver. The pulse varies much in frequency in different cases, and at different times in the same case: generally it is very rapid, especially when accompanied with much heat of skin.

The pain is sometimes severe, and may be referred exactly to the spot which subsequent examination shows to have been the seat of secondary inflammation; at other times it is not confined to any particular situation, but consists of general ill-defined feelings of short duration, and recurring at irregular intervals. The peculiarity of such sensations is best expressed by the terms applied to them by the patients themselves. "Catching pains all over", "soreness of the stomach", and "thrilling in the blood", not unfrequently accompany this disease.

Vomiting may occur, either as a symptom of constitutional disturbance, or as indicative of inflammation of an abdominal organ (Case xxvi). In the latter case, it is extremely obstinate, and the fluid ejected is generally of a green colour. Diarrhoea is a symptom of frequent occurrence, and appears to exercise a considerable influence on the course of the disease. Its appearance will not unfrequently be accompanied by relief of the other symptoms (Case iii); when it occurs, it is generally profuse, and little under the control of medicine, but, if checked, may be followed by a sudden change for the worse in the condition of the patient.

The intellect is seldom affected during the first stages of the complaint; but subsequently, in severe cases, restlessness, delirium, and coma, seldom fail to succeed each other. These symptoms are all peculiar, both in regard to the rapidity with which they make their appearance, and also the sudden manner in which they occasionally disappear. The disease may seem, within a few hours, to leave a part which it has first attacked, and to fall upon a different organ in some remote part of the body.

X. The post-mortem appearances observed in those who die in consequence of the introduction of vitiated fluids into the blood, cannot, for the most part, be distinguished from similar changes produced by other causes; yet there are some effects which are peculiar, and may be directly associated with the reception of foreign matter into the circulation. The most characteristic circumstance, attending the extension of disease to different organs of the body through the medium of the blood, is that several parts of these organs, or even different organs, will be simultaneously attacked. The disease will appear at once in various spots, which will become rapidly disorganized, while the surrounding textures will remain unaltered, either in structure or colour. The appearances observed upon dissection will vary according to the part attacked, and the stage of development in which the disease is found.

The lungs are the organs in which the successive changes may best be observed. When puriform fluid has entered the circulation, the first appearance produced in the structure of the lungs, is that of one or more congested or dilated veins[33] of very small diameter. This will be followed by a well defined spot, of much darker colour than the surrounding texture. Several of these spots will probably appear at the same time, and each one of them will soon become surrounded by a hard spherical patch of purple congestion. Effusion of lymph will now take place, commencing in the centre of each affected portion, and gradually extending towards its circumference. If the disease continue, each spot will suppurate, and the different parts will become softened and broken down, in the same order in which they were previously solidified.

The liver frequently becomes the seat of secondary inflammation. In the early stage, brownish-red spots may be observed scattered through its substance. These, as they extend, assume a bluish or slate-colour; and the structure of the liver thus affected is found to have lost its consistence, and to be very easily broken down by pressure. Every part affected here, as in the lungs, proceeds rapidly to suppuration; and the usual appearance presented after death, is that of several small circumscribed abscesses, around which the structure of the liver has been condensed only to a very small extent. It sometimes happens, that the larger veins in the liver become inflamed. These vessels, being held open by the firm structure of the part, are not so readily obliterated as in other situations; and it consequently happens, that the lymph and pus poured into them become irregularly mixed with the blood, more or less perfectly coagulated, which they contain: a very peculiar mottled appearance, resembling granite, is thus occasionally produced.

Affections of the spleen, produced by the introduction of foreign matter into the blood, are probably not so readily recognised as similar affections in the lungs and liver. For, although the spleen is often found to be diseased in those who die from infection of the blood, yet it is comparatively seldom that secondary abscesses have been found in it. In the accompanying table, containing twenty-three cases, some morbid appearance, not recognised as peculiarly the result of secondary inflammation, was observed in the spleen in no less than eight instances. So large a proportion of cases renders it probable, that the alterations observed have more than an accidental connexion with the disease of which the patient died, although they presented no characters which could be said to be peculiar to that disease. In well-marked cases of secondary affections of the spleen, one or more well defined, but frequently irregular indurations, of a chocolate colour, may be recognised; such patches are usually seen soon after the commencement of the complaint, and in a very short time become softened or broken down. The rapidity with which they lose their original character, may probably account for their being comparatively seldom observed in post-mortem examinations.

Deposits of lymph are sometimes met with in the kidneys; but these are of small extent, of a light colour, and resemble lymph deposited in consequence of ordinary inflammation. The patches of congestion, so characteristic of this disease in other organs, are not here observed. This may depend upon the peculiar disposition of the capillary system of the kidney. The blood has to pass through the Malpigian tufts, and may be purified, or altered in character, before it reaches the proper venous system of the organ.

In cases where purulent infection of the blood has been purposely produced, portions of the kidney will not unfrequently be found inflamed and firmer than natural; but, if the origin of the disease were not known these appearances could not be distinguished from those produced by inflammation of the kidney from other causes.

The skin is liable to be affected in three different forms. (See Cases i, ii, iii, ix, x, and xxxiv). The first of these occurs very rarely, and consists of small deposits of matter in the structure, or upon the surface of the skin, resembling in many respects the pustules of small-pox. The second form is also of rare occurrence, and consists of small congested spots on the surface of the skin. These are generally of a dark purple hue, but I have seen one case in which they were of a bright red colour. In this instance, a secondary abscess had formed in the knee-joint, and some pustules appeared upon the skin in the neighbourhood. A fortnight before the death of the patient, a number of small bright red spots made their appearance in different parts of the thigh and upper part of the leg; some of these were three or four lines in diameter while others were so small as not to be seen without attention; they appeared in accurately defined spots, of a brighter colour than the mucous membrane of the lips, and continued unchanged in appearance till death. The third form presents itself much more frequently than either of the others, although it has not hitherto much attracted the attention of pathologists, in connexion with purulent or other infection of the blood. It commences very suddenly, and frequently without any particular attention being directed to the part. A large circular patch of congestion, livid or purple in the centre, but becoming of a lighter colour towards the circumference, will form, usually upon some part of the lower extremities. The skin of the calf of the leg is perhaps more frequently attacked than that of any other part. In the centre of the congested portion, mortification very rapidly takes place, and is indicated by the part assuming a black or dull leaden colour. In some cases, it would be difficult to say where the mortification ceases, and the congestion begins; but in other instances, there is a distinct line of demarcation formed: a zone of bright red congestion will then occasionally surround the mortified part.

Some modifications of this third form of affection of the skin may be met with occasionally in the course of the disease. Blotches assuming a livid or dusky red appearance (which gradually fades into the colour of the surrounding skin), will present themselves in different parts (Case xxxvi), and terminate in thick exfoliation of the cuticle, or in small sloughs of the skin. In some instances, the superficial portions only of the skin are destroyed, and the parts beneath appear comparatively unaffected; small circumscribed portions of the outer layer of the skin will exfoliate, and the subjacent parts will heal without suppuration, by a process similar to that of scabbing (Case iii).

It is remarkable in this disease, that the most vascular parts are those which soonest lose their vitality. Thus, in the case last referred to, portions of the surface of the skin perished, while the deeper layers recovered; again, it is not unusual to observe the whole thickness of the skin destroyed, without any corresponding affection of the cellular membrane beneath. The quantity of blood sent to a part would thus appear to favour mortification in this disease. The reason of this peculiarity will be considered in the next section.

In two of the instances recorded in the Appendix (Cases xxii and xxvi), the lining membrane of the rectum was found of a very dark colour, and in one it had assumed a greenish appearance. This discoloration was at first looked upon as some accidental complication, or as depending upon previous disease. But M. Gaspard has noticed a similar condition, after the artificial introduction of putrid fluid into the blood.[34] In one of the experiments referred to, the mucous membrane of the intestines was everywhere healthy, except in the rectum and duodenum. In the former situation, the rugÆ were prominent, and of a violet colour; in the latter, the membrane was of the colour of pale lees of wine. From the coincidence thus observed, we are led to believe that the same condition which produces congestion in the skin, may produce an analogous affection of the mucous membrane. Nor must we omit to note, in connexion with this subject, the fact of the mucous membrane of the vagina being occasionally found of a dark purple colour in those who die of puerperal affections.

In the cellular membrane, serum, lymph, and pus, may be deposited, mixed with each other in various proportions. The surrounding vascularity, in these cases, is unusually small, and the lymph effused not properly organized; there is, consequently, no natural boundary to the disorganizing process, and the fluid secreted becomes infiltrated in the surrounding parts.

When the muscular structure is affected, suppuration takes place with great rapidity; portions of muscles may be found quite soft, and sometimes pultaceous, in circumscribed patches, around which the fibre is perfectly healthy. Pus is occasionally deposited on the exterior of muscles; and it will be then smeared over the surface, and rather infiltrated in the cellular tissue, than contained in a cyst. In the interior of muscles, there is the same absence of the natural limit to the inflammation; but, owing to the more compact structure of the part, the deposits of matter generally remain circumscribed.

The brain and its membranes frequently present diseased appearances in those who die from secondary inflammation; these, for the most part, may be altogether independent of any peculiar effects of the disease; but, in some cases, it appears probable that they are not altogether unconnected with it. In one of the accompanying cases, the pons Varolii and medulla oblongata were found of a pink colour, in consequence of congestion, where the system had become contaminated by the absorption of diseased secretion; and, in another, a layer of purulent lymph was found within the cavity of the arachnoid, accompanied by marks of inflammatory action in the fourth, and in one of the lateral ventricles.

The serous membranes are peculiarly liable to be attacked by secondary inflammation; and, when affected, suppurate with the greatest readiness. They generally exhibit but a slight degree of vascularity, and sometimes scarcely appear more injected than in their natural condition. In the peritoneal cavity, large quantities of unorganised lymph are frequently poured out, mixed with turbid serum or pus. The synovial membranes of joints, when affected, appear to run directly into suppuration, and will become distended with pus in a very short space of time. The pleura, on the other hand, will seldom suppurate at first; but lymph will be deposited upon its surface, and its cavity will contain turbid serum, occasionally mixed with blood.

XI. In the first sections, the changes produced in the blood, both in and out of the body, by the admixture of purulent or diseased secretions, were considered; and, in the last section, the post-mortem appearances observed in the different organs of those who have died in consequence of secondary inflammations, have been described. It now remains to connect these two series of observations, and to trace the relation that they bear to each other.

The most direct way in which diseased blood produces disease in the parts to which it is conveyed, is by communicating to them its own condition. Even foreign substances, which have no natural connexion with the body, may, in this way, be conveyed in the blood, and deposited in the organs of the body. Hunter relates a case,[35] in which a house-painter, who had been paralytic in his hands and legs for a considerable time, had his thigh broken, and died, about three weeks after, of the accident: "On examining the body, after death, the muscles, particularly those of the arms, had lost their natural colour; but, instead of being ligamentous and semitransparent, as happens in common paralysis, they were opaque, resembling exactly in appearance parts steeped in a solution of Goulard's extract. From this case it appears, that the lead had been evidently carried along with the blood into the muscles themselves. The blood can thus receive and retain extraneous matter capable of destroying the solids."

If foreign matter may, in this way, be conveyed to different parts of the frame, and there produce its chemical effects, it will readily be admitted, that a mechanical or vital action commenced in the blood,[36] may be continued in it when moved to a different part of the body.

In those who die of secondary inflammations, the result of such actions may frequently be traced from the seat of the primary injury even to the heart itself; and, as it has already been shown that contaminated blood will communicate morbid action to the vessels in which it is contained (section iii), there no longer remains any difficulty in accounting for the sudden way in which this disease may fall upon a particular organ, or the unexpected manner in which the symptoms may shift from one part of the body to another. The conditions of the blood, which may be observed upon dissection, in this disease, so far as they tend to illustrate the present subject, may be included in two general expressions: 1st, those in which the blood has had a preternatural tendency to coagulate impressed upon it; and, 2nd, those in which its coagulating power has, to a greater or less extent, been impaired. In one case, the blood is generally found of a dark colour, with firm, and sometimes adherent coagula in the vessels; in the other, it is thin and fluid.

When a preternatural tendency to coagulate has been impressed upon the blood, it will lodge in different parts of the vascular system, in situations which are most favourable to such an action; when, on the contrary, it has lost its coagulating power, extensive effusions may be expected, or the symptoms included under the term "gangrenous diathesis" may manifest themselves.

As the aggregate diameter of the vessels in the body decreases, the blood in them flows with greater rapidity and force; and when near the heart, it is placed in circumstances unfavourable to coagulation, in consequence of the rapid motion there communicated to it; and we accordingly find that, although adherent coagula may be formed in the veins leading from the seat of injury, and may be traced thence through other larger vessels, they will usually terminate abruptly, when these open into the vena cava. But when the blood arrives in the cavities of the heart, the tendency to coagulate may again manifest itself. Diseased coagula, presenting a "mottled appearance, partly brown, and partly of a dirty yellow colour", or "dark coloured, and partly composed of a yellowish grey opaque substance", or "with portions inelastic, and of an opaque yellow colour", will be found entangled among the projecting fibres of the auricles and ventricles. In the arteries, the blood is in the most unfavourable circumstances for coagulation during life, in consequence of the comparative smallness of their diameters, and the succession of impulses communicated to their contents; but even here, diseased and adherent coagula may be found in cases of secondary inflammations.

M. Cruveilhier[37] relates an instance in which, after child-birth, the pulmonary artery was found filled with coagula following its divisions. The principal clot had lost its colour, and was adherent to the sides of the vessel, and contained in its centre puriform fluid.

In another case, following the operation for necrosis, the following post-mortem appearances were observed. The left lung presented, in several places, patches of red hepatization, perfectly defined, and resembling so many spots of lobular inflammation. When cut into, these patches presented several puncta of puriform fluid. The veins of the lung contained fibrinous-looking coagula blocking up their cavities; and in the centre of these coagula was a whitish purulent looking fluid.

The diseased condition of the blood may thus be traced visibly from the original wound, through the larger vessels, to the heart, and again from the heart to the capillary system. The disposition to coagulate, once impressed upon the blood, is not destroyed by that fluid being conveyed to a different part of the body: the action may be retarded by motion in, as well as out of the body, but will nevertheless occur when it is placed under more favourable circumstances.

These circumstances, in the living vessels, are when the blood becomes separated into small quantities, and when it moves slowly along the capillaries. The blood will then coagulate in circumscribed patches,[38] as illustrated in the first characteristic marks of secondary disease which have already been mentioned as occurring in the lungs, the liver, the spleen, and the skin. The accompanying plate is taken from the lung of a donkey in which purulent fluid had been made to circulate with the blood. The stagnation of the blood, when the pus was first introduced, was mechanically prevented, and the livid spots produced by its subsequent coagulation in the capillaries of the lungs has been very faithfully represented. (See Experiment No. vi.)

"Besides the disposition for coagulation," observes Mr. Hunter, "the blood has, under certain circumstances, a disposition for the separation of the red globules, and probably of all its parts; for I have reason to believe, that a disposition for a separation of the red part and coagulation, are not the same thing, but arise from two different principles. This is always observable in bleeding; for if we tie up an arm and do not bleed immediately, the first blood that flows from the orifice, or that which has stagnated for some time in the veins, will soonest separate into its three constituent parts: this circumstance exposes more of the coagulating lymph at the top, which is supposed by the ignorant to indicate more inflammation, while the next quantity taken suspends its red parts in the lymph, and gives the idea that the first small quantity had been of such service at the time of its flowing, as to have altered for the better the whole mass of blood. Best, therefore, maybe regarded as one of the immediate causes of the separation." Hunter, p. 29.

This disposition of the blood to separate into its constituent parts is evinced in a very marked degree in one class of secondary affections. Extensive effusions of serum, lymph, and pus, mixed in different proportions, will take place in the serous cavities of the body, and become infiltrated in the cellular membrane, accompanied with very slight indications of inflammatory action. The colouring matter of the blood will also sometimes become effused with its other parts; but when this is the case, the blood will be found to have lost its coagulating power: in this respect presenting a direct contrast to the effusion from a healthy wounded vessel. The lymph deposited will be found lying in unorganized flakes, wanting its usual adhesive properties, and very slightly attached to parts, presenting little or no increased vascularity. The rapid manner in which these depositions take place, shows that they are separated from the blood without undergoing any very elaborate process. In this condition of the system, any organ upon which the disease falls, may rapidly become disorganized, or may readily mortify; and, after death, a tendency to rapid decomposition will be manifested. The veins on the surface of the body may frequently be traced as dark blue lines, as though the skin covering them were stained by the colouring matter of the blood. The lungs and other organs may, under these circumstances, be found in every grade of disorganization, till they present all the characteristics of gangrene: even the peculiar fetor which accompanies mortification of the lung, will, in some instances, be present. A tendency to the formation of petechial spots may also be observed in different parts; and even the organs which do not appear to have been the peculiar seat of the disease, will be found to have lost their consistency, and to break down upon comparatively slight pressure.

Mr. Hunter found, that in proportion as the blood retained the power of coagulation, it had the power of resisting putrefaction; and conversely, we observe that, in this class of cases, the deficiency of the former is accompanied in a marked manner by the absence of the latter.

The two conditions of the blood which have now been mentioned, appear to bear a direct relation to the two classes of post-mortem appearances, observed in cases of secondary inflammations: the first being generally connected with congestion of different organs during the first stages of the disease, the second with extensive effusions, accompanied with comparatively little vascularity.

XII. The treatment of secondary inflammations naturally divides itself into local and constitutional, both as regards the primary lesion and the subsequent affections. The circumstances which interfere with union by the first intention in veins, have been shown to be the same as those which precede the formation of purulent deposits, in a large class of cases. Whatever then tends to favour the healthy reparation of a wounded vein, may be regarded as affording security against any subsequent disease; and the chief point in the local treatment is, perhaps, to prevent any accidental circumstances from interfering with the natural process of repair. When the powers of the constitution are enfeebled, even the natural motions of a part may interfere with recovery, and rest sometimes becomes an important object in the treatment. How necessary this is after child-birth, when the divided veins are being closed, every one who has attended such cases practically knows.

Again, after bleeding, the arm will inflame in a much greater proportion of cases, when the patient is obliged to follow his usual occupation, or when, from accidental circumstances (as from the pain experienced in Case i), the arms are kept in motion. It has occurred to me, to see the symptoms of purulent deposits set in, on the day following prolonged attempts to bring fractured portions of bone into position. In all such cases, any external violence (as in Experiment No. vi), or even the motion of the body, as in Dr. Davis's case (section iv) may loosen the coagula formed, either between the wounded edges, or in the cavities of veins.

In the treatment of the local injury, a valuable hint has been left us by Mr. Hunter, connected directly with the consideration of the pathology of the disease. "The way in which sore arms after bleeding come on, shows plainly that they arise from the wound not healing by the first intention"; and he recommends that the two sides of the vein should be approximated by a compress, until union of the divided edges has taken place.

It has been shown upon very high authority, that the sides of a vein do not unite after venesection (as has sometimes been presumed to be Mr. Hunter's opinion); but that the divided edges only of the vessel are agglutinated by the coagulum, which "serves as a bed to the new membrane." But the case is different, should this first attempt at union fail; the sides of the vessel may then become united, and its cavity for a time obstructed (section iv). The approximation of the sides of the veins would materially facilitate this action, which is the natural security, under the circumstances, against the admission of foreign matter. When an abscess is suspected to have formed in a vein, a similar mode of treatment is recommended by Hunter; the compress, in this case, being placed between the inflamed part and the centre of the circulation. In the pathological museum of the College of Surgeons, one of Mr. Hunter's preparations (No. 1728) exhibits such a case, where, from the imperfect union of a vein, the contents of the abscess had become mixed with the blood.

As the process of reparation has been variously described by authors, so the different theories propounded have led to different kinds of treatment. At the Veterinary College, even within the last few years, it was publicly taught, that a coagulum in a vein was a foreign substance, and ought to be removed; and the jugular vein in horses which had been bled, was sometimes slit up for several inches, in order to remove the coagula which formed in successive portions of its course.

That a coagulum in a vein may be an irritating substance has been fully proved (sections i and ii); but the irritation depends upon the accidental admixture of foreign matter: and the inflammation of the veins, produced by the contact of impure blood, requires to be carefully distinguished from the natural mode of union by the first intention.

To remove coagula which have formed round purulent secretion (if such could be recognised), might be to remove a cause of irritation; but to remove them in ordinary cases, is to remove the very means prepared by nature for the restoration and safety of the part. In operations involving large vessels, the local conditions which may influence the actions in the veins, appear not to have been fully determined; for while some surgeons regard the tying or cutting of a vein as a serious operation, others are in the habit of doing it without any unusual precaution. In operations upon hÆmorrhoidal tumours, the veins involved are of some size, and in two of the instances recorded in the Appendix, a ligature applied to them was followed by purulent deposits. In the usual mode of passing a needle armed with a double ligature through the base of such a tumour, the hÆmorrhoidal veins are necessarily sometimes wounded, and there is danger that, in tying the ligatures, the sides of a wounded vein may be drawn asunder. The vessel may thus be held open, and be in a similar condition to the vessels contained in bony structures.

A safe way of performing this operation, when admissible, is to destroy a portion of the mucous membrane with strong nitric acid. The blood in the vessels then becomes charred, and their cavities obstructed, till they are permanently closed by adhesive inflammation. Every means of treating a local injury which tends to produce healthy union or adhesion, may be considered in some sort as a preventive mode of treatment. Position, topical applications, bandages, and temperature, may all have their influence in producing these healthy actions; but, as the wounds which precede purulent deposits are generally characterized by feeble powers, those conditions which tend to invigorate the parts are principally indicated. "When action is greater than strength, whatever has the tendency to raise the power above irritability should be used: the object of this practice consists in bringing the strength of the constitution and parts as near upon a par with the action as possible, by which means, a kindly resolution, or suppuration may take place, according as the parts are capable of acting." The irritability of a wound frequently appears nothing else than a series of attempts to bring about an action, which it has not the power to accomplish: as soon as that is fulfilled, which the necessity of the parts demands for their healthy condition, irritation will cease. In such cases, everything that will confer strength to carry out the intended action, will prevent inflammation. But no local applications will be sufficient to produce this effect, unless the powers of the constitution are supported at the same time.

A heavy man received a wound in the back of his head from an iron spike; he was kept very low, complaining occasionally of want of food. Repeated hÆmorrhage took place at intervals of a day or two, which no local applications could suppress, and he ultimately died from loss of blood. The wound was found to extend through the bone into the lateral sinus, which contained only some fluid blood. No inflammatory action had taken place within the skull, nor had any attempt apparently been made to close the wounded vessel. Any vitiated secretion in contact with the lacerated edges of the vessel would, in such a case, have free access to the circulation.

The constitutional treatment of cases, liable to be succeeded by purulent deposits, is most important; for during the healing of the primary wound, the system may be influenced by remedies, which may be subsequently quite useless. It is evident, observes M. Cruveilhier,[39] that the treatment of phlebitis ought to be concentrated on the first period of the disease, viz., that of the coagulation of the blood; for as soon as pus has become mixed with the circulating blood, medicine is generally of no avail. When there are indications of the extension of inflammation along a vein, the mode of treatment usually adopted in this country has been the administration of calomel and opium; and, in France, general bleeding, but especially the application of large numbers of leeches. "We may subdue inflammation of veins, whatever their situation, by general blood-letting, and especially by local bleeding, repeated sufficiently often and in sufficient quantities!"[40] It is true that patients recover after such treatment; but the published records of cases not unfrequently terminate with such a description as the following: "The patient was repeatedly bled, and with apparent relief every time, the blood being extremely sizy. Two days, however, previous to death, the vital principle was so exhausted as to need the use of cordials!!"

If the explanation of the mode of adhesion in veins already given be correct, neither the propriety of bleeding, nor of the administration of mercury, as a rule, derives much support from a consideration of the pathology of the disease. Careful comparative experience is still wanting, before we can form a satisfactory judgment of the value of these remedies. The theoretical views upon which they have been adopted, are confirmed neither by the statistical records of cases, nor by the principles of sound physiology. The numerical evidence which we have in some instances, even tends to indicate an opposite plan of treatment.

At a period when puerperal fever was rife, forty cases, attacked with some form of the disease, "were treated without any bleeding or leeching, or without any attempt to induce the constitutional effects of mercury; and of these, only two died."[41] "In irritable habits, when the inflammation becomes more diffused," says Mr. Hunter, "bleeding should be performed with great caution: even a quick, hard pulse, and sizy blood, are not always to be depended upon as sure indications of bleeding being the proper method of the resolution of the inflammation; more must be taken into the account. The kind of blood is of great consequence to be known; for although it should prove sizy, yet if it lies squat in the basin, and is not firm in texture, and if the symptoms at the same time are very violent, bleeding must be performed very sparingly, if at all; for I suspect, that under such a state of blood, if the symptoms continue, bleeding is not the proper mode of treatment. If we had medicines which, when given internally, could be taken into the constitution, and were endowed with a power of making the vessels contract, such, I apprehend, would be proper medicines. Bark has certainly this property, and is of singular service, I believe, in every inflammation attended with weakness; and therefore, I conceive, should be oftener given than is commonly done."

In bleeding women suffering from puerperal fever during an epidemic, in which the disease frequently terminated in purulent deposits, I have occasionally seen an irregular transparent bluish layer form upon the surface of the blood, almost immediately after the operation; in consequence of this, a repetition of the bleeding was sometimes had recourse to, when the subsequent stages of the disease appeared to indicate that it had not been required. The transparent layer of lymph on the surface of the blood, may, in such instances, be only an indication of its tendency to separate into its different parts, as previously described. Large bleedings, under such circumstances, inasmuch as they tend to diminish the already enfeebled power of coagulation in the blood, may predispose to the infection of the system, and to the formation of purulent deposits. The influence of mercury upon the system, as illustrated in Case xxvi, may have the same tendency.

The action of mercury, so far as it can be traced upon the surface of the body, is certainly unfavourable both to union by the first intention, and to adhesive inflammation; and, inasmuch as the safety of the patient, after an injury or wound, depends upon the due performance of these processes, its effect upon the system must be regarded as of, at least, doubtful advantage.

When salivation has been induced, serum is poured out, and the texture of the gums is loosened and rendered spongy. When lymph is effused upon the iris, the action of mercury loosens its adhesions, and dissolves its connexions; it cannot, therefore, be supposed that its effect upon the system should render the union of divided vessels stronger, or the newly-formed adhesions in wounds, firmer.

The cases in which purulent deposits usually form, indicate a debilitated state of constitution. They are of much more frequent occurrence in large towns than in the country, and in hospital than in private practice. The depressing influences which give rise to erysipelas, or puerperal fever, will also predispose to the formation of these abscesses; and as scanty diet, loss of blood, debilitating surgical operations, and over-crowded rooms, have been found among the causes of the former, so may they be looked upon as favouring the production of the latter.

The Treatment of Inflammation of the Veins, in which purulent deposits frequently originate, is thus spoken of, after matured observation: "All the experience that I have had on the subject, would lead me to believe that, like erysipelas, it has its origin in a low asthenic state of the system, and that those persons are especially liable to it, who have been much lowered by hÆmorrhage at the time of an operation, or by too scanty a diet afterwards. An operation is a shock upon the system, making a great demand upon the vital powers. The effects of this shock are often much aggravated by loss of blood, and a very scanty diet actually makes the patient more liable to some kinds of inflammation. Our mode of practice ought to be rather to sustain his powers by allowing him wholesome nourishment, and not to add to the influence of the other depressing causes, the still worse one of starvation."[42]

The lowering influence of mercury may be considered in a similar way. There can be little doubt that while, on the one hand, it favours the absorption of vitiated fluids, it may, on the other, render the system less able to resist the injurious consequences which they produce.

As many circumstances, besides mere debility, tend to depress the vital powers, so tonic medicines, and a generous diet, must not be looked upon as the only preventive modes of treatment. Each case that occurs in practice may present some peculiarity; in one case, the patient will be found to have previously suffered from diabetes; in another, from disease of the spleen; and in a third, from organic disease of the kidney; and, in each of these, a peculiar mode of treatment may be required.

The general management of this disease, after the formation of purulent deposits has commenced, is probably as little satisfactory as any that come under the notice of the surgeon. The whole character of the affection is characterized by what has been aptly designated as action without power. The excitement of the system will imitate all the acts of genuine inflammation, without any of its healthy results; and loss of energy will appear immediately after, or even arise in conjunction with, the first symptoms of increased action.

In the treatment of such cases, it must be borne in mind, that the secondary inflammations are not the disease, but the effect of a concealed cause, which may develope itself in any part of the system; and that, while the relief of one organ is sought by depletion or mercurial remedies, additional vigour may be given to the latent evil, so as to render it more ready to develope itself in some other part.

When purulent deposits occur, the sudden congestions, which indicate their commencement, are not accompanied by any reparative actions, and the lymph, which is effused in the second stage of their formation, is not so disposed as to circumscribe and limit the inflammation; there is, therefore, no natural process by means of which such collections of fluid can be evacuated; hence, when situated near the surface, they should be opened as soon as they are detected. It will sometimes happen, that, after the symptoms of secondary inflammation of internal organs have commenced, an abscess will present itself near the surface of the body, and relief will be afforded to the part first affected; at other times, an obstinate and violent diarrhoea will precede recovery. Although the mode of treatment adopted may have little influence either in bringing on, or checking, such salutary actions, it is important to watch their occurrence, and perhaps still more important, to be careful not to mistake a remedial action for a symptom of the disease.

"What treatment," says Cruveilhier, "shall we oppose to purulent infection? To this question experience is as yet dumb, while theory would seem to point to diffusible stimuli and tonics; to ammonia, quinine, and sudorifics; to hot external applications, to the vapour baths, to purgatives, and especially to emetics; to tartarized antimony, in large doses; to vesicatories, and to strong diuretics. Calomel has been extensively employed, to create a fluxion from the intestinal mucous membrane; but all these means have failed as signally in my hands as in those of others; yet, when the injection of putrid matters into the veins of living animals has been followed by abundant and very fetid evacuations, they have usually got well. It is a fundamental fact of pathology, that the intestinal canal is chiefly affected in diseases caused by miasmata. I am certain that diseases resulting from purulent infection would not be stamped with the seal of incurability, and that nature, seconded by art, would triumph in the majority of cases, if the pus, which is incessantly renewed, did not incessantly renew the sources of infection. As soon as constitutional symptoms manifest themselves, neither general nor local bleeding affords any advantage. A portion of the materies morbi is, no doubt, abstracted with the blood; but, as it is constantly being reproduced, the constitution is only deprived of the power it would otherwise have of resisting the disease."[43] In accordance with this remark, M. Gaspard found that animals, which recovered after the injection of a certain quantity of pus into their veins, often died when the experiment was repeated. The recovery was usually preceded by black, liquid, and extremely fetid evacuations, which often seemed to afford immediate relief. When such evacuations have taken place in other diseases, the gall-bladder has been found distended with black bile;[44] and it appears probable that the liver, in these cases, is one of the principal organs through which the cleansing of the system is attempted. If the supply of morbid matter to the system could be checked, mercurial action, in this stage of the disease, might be of service, by enabling the liver, or other organs, to throw off their vitiated secretions. When patients recover from purulent deposits (Cases iii and xxvii), they are often left in a debilitated and languid state, in which ordinary tonics exercise little influence. The consequences of the disease appear to hang about the system, long after the cause which gave rise to it has ceased. The pulse will sometimes continue irritable, and there will be a tendency to derangement of the secretions of the skin, bowels, and other organs, accompanied by occasional slight attacks of fever. In this condition, an alterative course of mercury, combined with sarsaparilla, has been found beneficial. These remedies, by stimulating the activity of the excreting organs, may assist the constitution in throwing off the disease; and their mode of action may be the same as in other cases, where the system has been infected by an animal poison.