In this Appendix I shall present the reader with the communications of several of my friends on the subject of the preceding work. Among them I should with pleasure have inserted some curious experiments, made by Dr. Hulme of Halifax, on the air extracted from Buxton water, and on the impregnation of several fluids, with different kinds of air; but that he informs me he proposes to make a separate publication on the subject.

NUMBER I.

It having been suggested, that air arising from a fermenting mixture of chalk and oil of vitriol might carry up with it a small portion of the vitriolic acid, rendered volatile by the act of fermentation; I made the following experiments, in order to discover whether the acidulous taste, which water impregnated with such air affords, was owing to the presence of any acid, or only to the fixed air it had absorbed.

Experiment I.

I mixed a tea-spoonful of syrup of violets with an ounce of distilled water, saturated with fixed air procured from chalk by means of the vitriolic acid; but neither upon the first mixture, nor after standing 24 hours, was the colour of the syrup at all changed, except by its simple dilution.

Experiment II.

A portion of the same distilled water, unimpregnated with fixed air, was mixed with the syrup in the same proportion: not the least difference in colour could be perceived betwixt this and the above-mentioned mixture.

Experiment III.

One drop of oil of vitriol being mixed with a pint of the same distilled water, an ounce of this water was mixed with a tea-spoonful of the syrup. This mixture was very distinguishable in colour from the two former, having a purplish cast, which the others wanted.

Experiment IV.

The distilled water impregnated with so small a quantity of vitriolic acid, having a more agreeable taste than when alone, and yet manifesting the presence of an acid by means of the syrup of violets; I subjected it to some other tests of acidity. It formed curds when agitated with soap, lathered with difficulty, and very imperfectly; but not the least ebullition could be discovered upon dropping in spirit of sal ammoniac, or solution of salt of tartar, though I had taken care to render the latter free from causticity by impregnating it with fixed air.

Experiment V.

The distilled water saturated with fixed air neither effervesced, nor shewed any clouds, when mixed with the fixed or volatile alkali.

Experiment VI.

No curd was formed by pouring this water upon an equal quantity of milk, and boiling them together.

Experiment VII.

When agitated with soap, this water produced curds, and lathered with some difficulty; but not so much as the distilled water mixed with vitriolic acid in the very small proportion above-mentioned. The same distilled water without any impregnation of fixed air lathered with soap without the least previous curdling. River-water, and a pleasant pump-water not remarkably hard, were compared with these. The former produced curds before it lathered, but not quite in so great a quantity as the distilled water impregnated with fixed air: the latter caused a stronger curd than any of the others above-mentioned.

Experiment VIII.

Apprehending that the fixed air in the distilled water occasioned the coagulation, or separation of the oily part of the soap, only by destroying the causticity of the lixivium, and thereby rendering the union less perfect betwixt that and the tallow, and not by the presence of any acid; I impregnated a fresh quantity of the same distilled water with fixed air, which had passed through half a yard of a wide barometer-tube filled with salt of tartar; but this water caused the same curdling with soap as the former had done, and appeared in every respect to be exactly the same.

Experiment IX.

Distilled water saturated with fixed air formed a white cloud and precipitation, upon being mixed with a solution of saccharum saturni. I found likewise, that fixed air, after passing through the tube filled with alkaline salt, upon being let into a phial containing a solution of the metalic salt in distilled water, caused a perfect separation of the lead, in the form of a white powder; for the water, after this precipitation, shewed no cloudiness upon a fresh mixture of the substances which had before rendered it opaque.

NUMBER II.

Leeds, Feb. 15th, 1772.

Reverend Sir,

Having lately experienced the good effects of fixed air in a putrid fever, applied in a manner, I believe not heretofore made use of, I thought it proper to inform you of the agreeable event, as the method of applying this powerful corrector of putrefaction took its rise principally from your observations and experiments on factitious air; and now, at your request, I send the particulars of the case I mentioned to you, as far as concerns the administration of this remedy.

January 8, 1772, Mr. Lightbowne, a young gentleman who lives with me, was seized with a fever, which, after continuing about ten days, began to be attended with those symptoms that indicate a putrescent state of the fluids.

18th, His tongue was black in the morning when I first visited him, but the blackness went off in the day-time upon drinking: He had begun to doze much the preceding day, and now he took little notice of those that were about him: His belly was loose, and had been so for some days: his pulse beat 110 strokes in a minute, and was rather low: he was ordered to take twenty-five grains of Peruvian bark with five of tormentil-root in powder every four hours, and to use red wine and water cold as his common drink.

19th, I was called to visit him early in the morning, on account of a bleeding at the nose which had come on: he lost about eight ounces of blood, which was of a loose texture: the hÆmorrhage was suppressed, though not without some difficulty, by means of tents made of soft lint, dipped in cold water strongly impregnated with tincture of iron, which were introduced within the nostrils quite through to their posterior apertures; a method which has never yet failed me in like cases. His tongue was now covered with a thick black pellicle, which was not diminished by drinking: his teeth were furred with the same kind of sordid matter, and even the roof of his mouth and sauces were not free from it: his looseness and stupor continued, and he was almost incessantly muttering to himself: he took this day a scruple of the Peruvian bark with ten grains of tormentil every two or three hours: a starch clyster, containing a drachm of the compound powder of bole, without opium, was given morning and evening: a window was set open in his room, though it was a severe frost, and the floor was frequently sprinkled with vinegar.

20th, He continued nearly in the same state: when roused from his dozing, he generally gave a sensible answer to the questions asked him; but he immediately relapsed, and repeated his muttering. His skin was dry, and harsh, but without petechiÆ. He sometimes voided his urine and fÆces into the bed, but generally had sense enough to ask for the bed-pan: as he now nauseated the bark in substance, it was exchanged for Huxham's tincture, of which he took a table spoonful every two hours in a cup full of cold water: he drank sometimes a little of the tincture of roses, but his common liquors were red wine and water, or rice-water and brandy acidulated with elixir of vitriol: before drinking, he was commonly requested to rinse his mouth with water to which a little honey and vinegar had been added. His looseness rather increased, and the stools were watery, black, and foetid: It was judged necessary to moderate this discharge, which seemed to sink him, by mixing a drachm of the theriaca Andromachi with each clyster.

21st. The same putrid symptoms remained, and a subsultus tendinum came on: his stools were more foetid; and so hot, that the nurse assured me she could not apply her hand to the bed-pan, immediately after they were discharged, without feeling pain on this account: The medicine and clysters were repeated.

Reflecting upon the disagreeable necessity we seemed to lie under of confining this putrid matter in the intestines, lest the evacuation should destroy the vis vitÆ before there was time to correct its bad quality, and overcome its bad effects, by the means we were using; I considered, that, if this putrid ferment could be more immediately corrected, a stop would probably be put to the flux, which seemed to arise from, or at least to be encreased by it; and the fomes of the disease would likewise be in a great measure removed. I thought nothing was so likely to effect this, as the introduction of fixed air into the alimentary canal, which, from the experiments of Dr. Macbride, and those you have made since his publication, appears to be the most powerful corrector of putrefaction hitherto known. I recollected what you had recommended to me as deserving to be tried in putrid diseases, I mean, the injection of this kind of air by way of clyster, and judged that in the present case such a method was clearly indicated.

The next morning I mentioned my reflections to Dr. Hird and Dr. Crowther, who kindly attended this young gentleman at my request, and proposed the following method of treatment, which, with their approbation, was immediately entered upon. We first gave him five grains of ipecacuanha, to evacuate in the most easy manner part of the putrid colluvies: he was then allowed to drink freely of brisk orange-wine, which contained a good deal of fixed air, yet had not lost its sweetness. The tincture of bark was continued as before; and the water which he drank along with it, was impregnated with fixed air from the atmosphere of a large vat of fermenting wort, in the manner I had learned from you. Instead of the astringent clyster, air alone was injected, collected from a fermenting mixture of chalk and oil of vitriol: he drank a bottle of orange-wine in the course of this day, but refused any other liquor except water and his medicine: two bladders full of air were thrown up in the afternoon.

23d. His stools were less frequent; their heat likewise and peculiar foetor were considerably diminished; his muttering was much abated, and the subsultus tendinum had left him. Finding that part of the air was rejected when given with a bladder in the usual way, I contrived a method of injecting it which was not so liable to this inconvenience. I took the flexible tube of that instrument which is used for throwing up the fume of tobacco, and tied a small bladder to the end of it that is connected with the box made for receiving the tobacco, which I had previously taken off from the tube: I then put some bits of chalk into a six ounce phial until it was half filled; upon these I poured such a quantity of oil of vitriol as I thought capable of saturating the chalk, and immediately tied the bladder, which I had fixed to the tube, round the neck of the phial: the clyster-pipe, which was fastened to the other end of the tube, was introduced into the anus before the oil of vitriol was poured upon the chalk. By this method the air passed gradually into the intestines as it was generated; the rejection of it was in a great measure prevented; and the inconvenience of keeping the patient uncovered during the operation was avoided.

24th, He was so much better, that there seemed to be no necessity for repeating the clysters: the other means were continued. The window of his room was now kept shut.

25th, All the symptoms of putrescency had left him; his tongue and teeth were clean; there remained no unnatural blackness or foetor in his stool, which had now regained their proper consistence; his dozing and muttering were gone off; and the disagreeable odour of his breath and perspiration was no longer perceived. He took nourishment to-day, with pleasure; and, in the afternoon, sat up an hour in his chair.

His fever, however, did not immediately leave him; but this we attributed to his having caught cold from being incautiously uncovered, when the window was open, and the weather extremely severe; for a cough, which had troubled him in some degree from the beginning, increased, and he became likewise very hoarse for several days, his pulse, at the same time, growing quicker: but these complaints also went off, and he recovered, without any return of the bad symptoms above-mentioned.

I am, Reverend Sir,
Your obliged humble Servant,
Wm. Hey.

POSTSCRIPT

October 29, 1772.

Fevers of the putrid kind have been so rare in this town, and in its neighbourhood, since the commencement of the present year, that I have not had an opportunity of trying again the effects of fixed air, given by way of clyster, in any case exactly similar to Mr. Lightbowne's. I have twice given water saturated with fixed air in a fever of the putrescent kind, and it agreed very well with the patients. To one of them the aËrial clysters were administred, on account of a looseness, which attended the fever, though the stools were not black, nor remarkably hot or foetid.

These clysters did not remove the looseness, though there was often a greater interval than usual betwixt the evacuations, after the injection of them. The patient never complained of any uneasy distention of the belly from the air thrown up, which, indeed, is not to be wondered at, considering how readily this kind of air is absorbed by aqueous and other fluids, for which sufficient time was given, by the gradual manner of injecting it. Both those patients recovered though the use of fixed air did not produce a crisis before the period at which such fevers usually terminate. They had neither of them the opportunity of drinking such wine as Mr. Lightbowne took, after the use of fixed air was entered upon; and this, probably, was some disadvantage to them.

I find the methods of procuring fixed air, and impregnating water with it, which you have published, are preferable to those I made use of in Mr. Lightbowne's case.

The flexible tube used for conveying the fume of tobacco into the intestines, I find to be a very convenient instrument in this case, by the method before-mentioned (only adding water to the chalk, before the oil of vitriol is instilled, as you direct) the injection of air may be continued at pleasure, without any other inconvenience to the patient, than what may arise from his continuing in one position during the operation, which scarcely deserves to be mentioned, or from the continuance of the clyster-pipe within the anus, which is but trifling, if it be not shaken much, or pushed against the rectum.

When I said in my letter, that fixed air appeared to be the greatest corrector of putrefaction hitherto known, your philosophical researches had not then made you acquainted with that most remarkably antiseptic property of nitrous air. Since you favoured me with a view of some astonishing proofs of this, I have conceived hopes, that this kind of air may likewise be applied medicinally to great advantage.

W. H.

NUMBER III.

These Observations on the Medicinal Uses of Fixed Air have been before published in the Second Volume of my Essays; but are here reprinted with considerable additions. They form a part of an experimental inquiry into this interesting and curious branch of Physics; in which the friendship of Dr. Priestley first engaged me, in concert with himself.

Manchester, March 16, 1774.

In a course of Experiments, which is yet unfinished, I have had frequent opportunities of observing that fixed air may in no inconsiderable quantity be breathed without danger or uneasiness. And it is a confirmation of this conclusion, that at Bath, where the waters copiously exhale this mineral spirit,[15] the bathers inspire it with impunity. At Buxton also, where the Bath is in a close vault, the effects of such effluvia, if noxious, must certainly be perceived.

Encouraged by these considerations, and still more by the testimony of a very judicious Physician at Stafford, in favour of this powerful antiseptic remedy, I have administered fixed air in a considerable number of cases of the Phthisis Pulmonalis, by directing my patients to inspire the steams of an effervescing mixture of chalk and vinegar; or what I have lately preferred, of vinegar and potash. The hectic fever has in several instances been considerably abated, and the matter expectorated has become less offensive, and better digested. I have not yet been so fortunate in any one case, as to effect a cure; although the use of mephitic air has been accompanied with proper internal medicines. But Dr. Withering, the gentleman referred to above, informs me, that he has been more successful. One Phthisical patient under his care has by a similar course intirely recovered; another was rendered much better; and a third, whose case was truly deplorable, seemed to be kept alive by it more than two months. It may be proper to observe that fixed air can only be employed with any prospect of success, in the latter stages of the phthisis pulmonalis, when a purulent expectoration takes place. After the rupture and discharge of a Vomica also, such a remedy promises to be a powerful palliative. Antiseptic fumigations and vapours have been long employed, and much extolled in cases of this kind. I made the following experiment, to determine whether their efficacy, in any degree, depends on the separation of fixed air from their substance.

One end of a bent tube was fixed in a phial full of lime-water; the other end in a bottle of the tincture of myrrh. The junctures were carefully luted, and the phial containing the tincture of myrrh was placed in water, heated almost to the boiling point, by the lamp of a tea-kettle. A number of air-bubbles were separated, but probably not of the mephitic kind, for no precipitation ensued in the lime water. This experiment was repeated with the tinct. tolutanÆ, ph. ed. and with sp, vinos. camp. and the result was entirely the same. The medicinal action therefore of the vapours raised from such tinctures, cannot be ascribed to the extrication of fixed air; of which it is probable bodies are deprived by chemical solution as well as by mixture.

If mephitic air be thus capable of correcting purulent matter in the lungs, we may reasonably infer it will be equally useful when applied externally to foul ulcers. And experience confirms the conclusion. Even the sanies of a cancer, when the carrot poultice failed, has been sweetened by it, the pain mitigated, and a better digestion produced. The cases I refer to are now in the Manchester infirmary, under the direction of my friend Mr. White, whose skill as a surgeon, and abilities as a writer are well known to the public.

Two months have elapsed since these observations were written,[16] and the same remedy, during that period, has been assiduously applied, but without any further success. The progress of the cancers seems to be checked by the fixed air; but it is to be feared that a cure will not be effected. A palliative remedy, however, in a disease so desperate and loathsome, may be considered as a very valuable acquisition. Perhaps nitrous air might be still more efficacious. This species of factitious air is obtained from all the metals except zinc, by means of the nitrous acid; and Dr. Priestley informs me, that as a sweetener and antiseptic it far surpasses fixed air. He put two mice into a quantity of it, one just killed, the other offensively putrid. After twenty-five days they were both perfectly sweet.

In the ulcerous sore throat much advantage has been experienced from the vapours of effervescing mixtures drawn into the fauces[17]. But this remedy should not supersede the use of other antiseptic applications.[18]

A physician[19] who had a very painful apthous ulcer at the point of his tongue, found great relief, when other remedies failed, from the application of fixed air to the part affected. He held his tongue over an effervescing mixture of potash and vinegar; and as the pain was always mitigated, and generally removed by this vaporisation, he repeated it, whenever the anguish arising from the ulcer was more than usually severe. He tried a combination of potash and oil of vitriol well diluted with water; but this proved stimulant and increased his pain; probably owing to some particles of the acid thrown upon the tongue, by the violence of the effervescence. For a paper stained with the purple juice of radishes, when held at an equal distance over two vessels, the one containing potash and vinegar, the other the same alkali and Spiritus vitrioli tenuis, was unchanged by the former, but was spotted with red, in various parts, by the latter.

In malignant fevers wines abounding with fixed air may be administered, to check the septic ferment, and sweeten the putrid colluvies in the primÆ viÆ. If the laxative quality of such liquors be thought an objection to the use of them, wines of a greater age may be given, impregnated with mephitic air, by a simple but ingenious contrivance of my friend Dr. Priestley.[20]

The patient's common drink might also be medicated in the same way. A putrid diarrhoea frequently occurs in the latter stage of such disorder, and it is a most alarming and dangerous symptom. If the discharge be stopped by astringents, a putrid fomes is retained in the body, which aggravates the delirium and increases the fever. On the contrary, if it be suffered to take its course, the strength of the patient must soon be exhausted, and death unavoidably ensue. The injection of mephitic air into the intestines, under these circumstances, bids fair to be highly serviceable. And a case of this deplorable kind, has lately been communicated to me, in which the vapour of chalk and oil of vitriol conveyed into the body by the machine employed for tobacco clysters, quickly restrained the diarrhoea, corrected the heat and foetor of the stools, and in two days removed every symptom of danger[21]. Two similar instances of the salutary effects of mephitic air, thus administered, have occurred also in my own practice, the history of which I shall briefly lay before the reader. May we not presume that the same remedy would be equally useful in the Dysentery? The experiment is at least worthy of trial.

Mr. W——, aged forty-four years, corpulent, inactive, with a short neck, and addicted to habits of intemperance, was attacked on the 7th of July 1772, with symptoms which seemed to threaten an apoplexy. On the 8th, a bilious looseness succeeded, with a profuse hoemorrhage from the nose. On the 9th, I was called to his assistance. His countenance was bloated, his eyes heavy, his skin hot, and his pulse hard, full, and oppressed. The diarrhoea continued; his stools were bilious and very offensive; and he complained of griping pains in his bowels. He had lost, before I saw him, by the direction of Mr. Hall, a surgeon of eminence in Manchester, eight ounces of blood from the arm, which was of a lax texture; and he had taken a saline mixture every sixth hour. The following draught was prescribed, and a dose of rhubarb directed to be administered at night.

?. Aq. Cinnam. ten. ?j.
Succ. Limon. recent. ?ß.
Salis Nitri gr. xij. Syr. È Succo Limon. ?j. M. f. Haust.
4tis horis sumendus.

July 11. The Diarrhoea was more moderate; his griping pains were abated; and he had less stupor and dejection in his countenance. Pulse 90, not so hard or oppressed. As his stools continued to be foetid, the dose of rhubarb was repeated; and instead of simple cinnamon-water, his draughts were prepared with an infusion of columbo root.

12. The Diarrhoea continued; his stools were involuntary; and he discharged in this way a quantity of black, grumous, and foetid blood. Pulse hard and quick; skin hot; tongue covered with a dark fur; abdomen swelled; great stupor. Ten grains of columbo root, and fifteen of the Gummi rubrum astringens were added to each draught. Fixed air, under the form of clysters, was injected every second or third hour; and directions were given to supply the patient plentifully with water, artificially impregnated with mephitic air. A blister was also laid between his shoulders.

13. The Diarrhoea continued, with frequent discharges of blood; but the stools had now lost their foetor. Pulse 120; great flatulence in the bowels, and fulness in the belly. The clysters of fixed air always diminished the tension of the Abdomen, abated flatulence, and made the patient more easy and composed for some time after their injection. They were directed to be continued, together with the medicated water. The nitre was omitted, and a scruple of the Confect. Damocratis was given every fourth hour, in an infusion of columbo root.

14. The Diarrhoea was how checked, His other symptoms continued as before. Blisters were applied to the arms; and a drachm and a half of the Tinctura SerpentariÆ was added to each draught.

15. His pulse was feeble, quicker and more irregular. He dosed much; talked incoherently; and laboured under a slight degree of DyspnÆa. His urine, which had hitherto assumed no remarkable appearance, now became pale. Though he discharged wind very freely, his belly was much swelled, except for a short time after the injection of the air-clysters. The following draughts were then prescribed.

Directions were given to foment his feet frequently with vinegar and warm water.

16. He has had no stools since the 14th. His Abdomen is tense. No change in the other symptoms. The Tinct. Serpent. was omitted in his draughts, and an equal quantity of Tinct. RhÆi Sp. substituted in its place.

In the evening he had a motion to stool, of which he was for the first time so sensible, as to give notice to his attendants. But the discharge, which was considerable and slightly offensive, consisted almost entirely of blood, both in a coagulated and in a liquid state. His medicines were therefore varied as follows:

Red Port wine was now given more freely in his medicated water; and his nourishment consisted of sago and salep.

In this state, with very little variation, he continued for several days; at one time ostive, and at another discharging small quantities of fÆces, mixed with grumous blood. The air-clysters were continued, and the astringents omitted.

20. His urine was now of an amber colour, and deposited a slight sediment. His pulse was more regular, and although still very quick, abated in number ten strokes in a minute. His head was less confused, and his sleep seemed to be refreshing. No blood appeared in his stools, which were frequent, but small in quantity; and his Abdomen was less tense than usual. He was extremely deaf; but gave rational answers to the few questions which were proposed to him; and said he felt no pain.

21. He passed a very restless night; his delirium recurred; his pulse beat 125 strokes in a minute; his urine was of a deep amber colour when first voided; but when cold assumed the appearance of cow's whey. The Abdomen was not very tense, nor had he any further discharge of blood.

Directions were given to shave his head, and to wash it with a mixture of vinegar and brandy; the quantity of wine in his drink was diminished; and the frequent use of the pediluvium was enjoined. The air-clysters were discontinued, as his stools were not offensive, and his Abdomen less distended.

22. His pulse was now small, irregular, and beat 130 strokes in a minute. The Dyspnoea was greatly increased; his skin was hot, and bedewed with a clammy moisture; and every symptom seemed to indicate the approach of death. In this state he continued till evening, when he recruited a little. The next day he had several slight convulsions. His urine which was voided plentifully, still put on the appearance of whey when cold. Cordial and antispasmodic draughts, composed of camphor, tincture of castor, and Sp. vol. aromat. were now directed; and wine was liberally administered.

24. He rose from his bed, and by the assistance of his attendants walked across the chamber. Soon after he was seized with a violent convulsion, in which he expired.

To adduce a case which terminated fatally as a proof of the efficacy of any medicine, recommended to the attention of the public, may perhaps appear singular; but cannot be deemed absurd, when that remedy answered the purposes for which it was intended. For in the instance before us; fixed air was employed, not with an expectation that it would cure the fever, but to obviate the symptoms of putrefaction, and to allay the uneasy irritation in the bowels. The disease was too malignant, the nervous system too violently affected, and the strength of the patient too much exhausted by the discharges of blood which he suffered, to afford hopes of recovery from the use of the most powerful antiseptics.

But in the succeeding case the event proved more fortunate.

Elizabeth Grundy, aged seventeen, was attacked on the 10th of December 1772, with the usual symptoms of a continued fever. The common method of cure was pursued; but the disease increased, and soon assumed a putrid type.

On the 23d I found her in a constant delirium, with a subsultus tendinum. Her skin was hot and dry, her tongue black, her thirst immoderate, and her stools frequent, extremely offensive, and for the most part involuntary. Her pulse beat 130 strokes in a minute; she dosed much; and was very deaf. I directed wine to be administered freely; a blister to be applied to her back; the pediluvium to be used several times in the day; and mephitic air to be injected under the form of a clyster every two hours. The next day her stools were less frequent, had lost their foetor, and were no longer discharged involuntarily; her pulse was reduced to 110 strokes in the minute; and her delirium was much abated. Directions were given to repeat the clysters, and to supply the patient liberally with wine. These means were assiduously pursued several days; and the young woman was so recruited by the 28th, that the injections were discontinued. She was now quite rational, and not averse to medicine. A decoction of Peruvian bark was therefore prescribed, by the use of which she speedily recovered her health.

I might add a third history of a putrid disease, in which the mephitic air is now under trial, and which affords the strongest proof both of the antiseptic, and of the tonic powers of this remedy; but as the issue of the case remains yet undetermined (though it is highly probable, alas! that it will be fatal) I shall relate only a few particulars of it. Master D. a boy of about twelve years of age, endowed with an uncommon capacity, and with the most amiable dispositions, has laboured many months under a hectic fever, the consequence of several tumours in different parts of his body. Two of these tumours were laid open by Mr. White, and a large quantity of purulent matter was discharged from them. The wounds were very properly treated by this skilful surgeon, and every suitable remedy, which my best judgment could suggest, was assiduously administered. But the matter became sanious, of a brown colour, and highly putrid. A Diarrhoea succeeded; the patient's stools were intolerably offensive, and voided without his knowledge. A black fur collected about his teeth; his tongue was covered with AphthÆ; and his breath was so foetid, as scarcely to be endured. His strength was almost exhausted; a subsultus tendinum came on; and the final period of his sufferings seemed to be rapidly approaching. As a last, but almost hopeless, effort, I advised the injection of clysters of mephitic air. These soon corrected the foetor of the patient's stools; restrained his Diarrhoea; and seemed to recruit his strength and spirits. Within the space of twenty-four hours his wounds assumed a more favourable appearance; the matter discharged from them became of a better colour and consistence; and was no longer so offensive to the smell. The use of this remedy has been continued several days, but is now laid aside. A large tumour is suddenly formed under the right ear; swallowing is rendered difficult and painful; and the patient refuses all food and medicine. Nourishing clysters are directed; but it is to be feared that these will renew the looseness, and that this amiable youth will quickly sink under his disorder[22].

The use of wort from its saccharine quality, and disposition to ferment, has lately been proposed as a remedy for the Sea Scurvy. Water or other liquors, already abounding with fixed air in a separate state, should seem to be better adapted to this purpose; as they will more quickly correct the putrid disposition of the fluids, and at the same time, by their gentle stimulus[23] increase the powers of digestion, and give new strength to the whole system.

Dr. Priestley, who suggested both the idea and the means of executing it, has under the sanction of the College of Physicians, proposed the scheme to the Lords of the Admiralty, who have ordered trial to be made of it, on board some of his Majesty's ships of war. Might it not however give additional efficacy to this remedy, if instead of simple water, the infusion of malt were to be employed?

I am persuaded such a medicinal drink might be prescribed also with great advantage in scrophulous complaints, when not attended with a hectic fever; and in other disorders in which a general acrimony prevails, and the crasis of the blood is destroyed. Under such circumstances, I have seen vibices which spread over the body, disappear in a few days from the use of wort.

A gentleman who is subject to a scorbutic eruption in his face, for which he has used a variety of remedies with no very beneficial effect, has lately applied the fumes of chalk and oil of vitriol to the parts affected. The operation occasions great itching and pricking in the skin, and some degree of drowsiness, but evidently abates the serous discharge, and diminishes the eruption. This patient has several symptoms which indicate a genuine scorbutic Diathesis; and it is probable that fixed air, taken internally, would be an useful medicine in this case.

The saline draughts of Riverius are supposed to owe their antiemetic effects to the air, which is separated from the salt of wormwood during the act of effervescence. And the tonic powers of many mineral waters seem to depend on this principle. I was lately desired to visit a lady who had most severe convulsive reachings. Various remedies had been administered without effect, before I saw her. She earnestly desired a draught of malt liquor, and was indulged with half a pint of Burton beer in brisk effervescence. The vomitings ceased immediately, and returned no more. Fermenting liquors, it is well known, abound with fixed air. To this, and to the cordial quality of the beer, the favourable effect which it produced, may justly be ascribed. But I shall exceed my design by enlarging further on this subject. What has been advanced it is hoped, will suffice to excite the attention of physicians to a remedy which is capable of being applied to so many important medicinal purposes.

NUMBER IV.

Extract of a Letter from William Falconer, M.D. of Bath.

Jan 6, 1774,

Reverend Sir,

I once observed the same taste you mention (Philosophical Transactions, p. 156. of this Volume, p. 35.) viz. like tar water, in some water that I impregnated with fixed air about three years ago. I did not then know to what to attribute it, but your experiment seems to clear it up. I happened to have spent all my acid for raising effervescence, and to supply its place I used a bottle of dulcified spirit of nitre, which I knew was greatly under-saturated with spirit of wine; from which, as analogous to your observation, I imagine the effect proceeded.

As[24] to the coagulation of the blood of animals by fixed Air, I fear it will scarce stand the test of experiment, as I this day gave it, I think, a fair trial, in the following manner.

A young healthy man, at 20 years old, received a contusion by a fall, was instantly carried to a neighbouring surgeon, and, at my request, bled in the following manner.

I inserted a glass funnel into the neck of a large clear phial about ?x. contents, and bled him into it to about ?viii. By these means the blood was exposed to the air as little a time as possible, as it flowed into the bottle as it came from the orifice.

As soon as the quantity proposed was drawn, the bottle was carefully corked, and brought to me. It was then quite fluid, nor was there the least separation of its parts.

On the surface of this I conveyed several streams of fixed air (having first placed the bottle with the blood in a bowl of water, heated as nearly to the human heat as possible) from the mixture of the vitriolic acid and lixiv. tartar, which I use preferably to other alkalines, as being (as Dr. Cullen observes) in the mildest state, and therefore most likely to generate most air.

I shook the phial often, and threw many streams of air on the blood, as I have often practised with success for impregnating water; but could not perceive the smallest signs of coagulation, although it stood in an atmosphere of fixed air 20 minutes or more. I then uncorked the bottles, and poured off about ?ii to which I added about 6 or 7 gtts of spirit of vitriol, which coagulated it immediately. I set the remainder in a cold place and it coagulated, as near as I could judge, in the same time that blood would have done newly drawn from the vein.

P. 82. Perhaps the circumilance of putrid vegetables yielding all fixed and no inflammable air may be the causes of their proving so antiseptic, even when putrid, as appears by Mr. Alexander's Experiments.

P. 86. Perhaps the putrid air continually exhaled may be one cause of the luxuriancy of plants growing on dunghills or in very rich soils.

P. 146. Your observation that inflammable air consists of the union of some acid vapour with phlogiston, puts me in mind of an old observation of Dr. Cullen, that the oil separated from soap by an acid was much more inflammable than before, resembling essential oil, and soluble in V. sp.

I have tried fixed air as an antiseptic taken in by respiration, but with no great success. In one case it seemed to be of service, in two it seemed indifferent, and in one was injurious, by exciting a cough.

NUMBER V.

Extract of a Letter from Mr. William Bewley, of Great Massingham, Norfolk.

March 23, 1774.

Dear Sir,

When I first received your paper, I happened to have a process going on for the preparation of nitrous ether, without distillation.[25] I had heretofore always taken for granted that the elastic fluid generated in that preparation was fixed air: but on examination I found this combination of the nitrous acid with inflammable spirits, produced an elastic fluid that had the same general properties with the air that you unwillingly, though very properly, in my opinion, term nitrous; as I believe it is not to be procured without employing the nitrous acid, either in a simple state, or compounded, as in aqua regia. I shall suggest, however, by and by some doubts with respect to it's title to the appellation of air.

Water impregnated with your nitrous air certainly, as you suspected from it's taste, contains the nitrous acid. On saturating a quantity of this water with a fixed alcali, and then evaporating, &c. I have procured two chrystals of nitre. But the principal observations that have occurred to me on the subject of nitrous air are the following. My experiments have been few and made by snatches, under every disadvantage as to apparatus, &c. and with frequent interruptions; and yet I think they are to be depended upon.

My first remark is, that nitrous air does not give water a sensibly acid impregnation, unless it comes into contact, or is mixed with a portion of common or atmospherical air: and my second, that nitrous air principally consists of the nitrous acid itself, reduced to the state of a permanent vapour not condensable by cold, like other vapours, but which requires the presence and admixture of common air to restore it to its primitive state of a liquid. I am beholden for this idea, you will perceive, to your own very curious discovery of the true nature of Mr. Cavendish's marine vapour.

When I first repeated your experiment of impregnating water with nitrous air, the water, I must own tasted acid; as it did in one, or perhaps two trials afterwards; but, to my great astonishment, in all the following experiments, though some part of the factitious air, or vapour, was visibly absorbed by the water, I could not perceive the latter to have acquired any sensible acidity. I at length found, however, that I could render this same water very acid, by means only of the nitrous air already included in the phial with it. Taking the inverted phial out of the water, I remove my finger from the mouth of it, to admit a little of the common air, and instantly replace my finger. The redness, effervescence, and diminution take place. Again taking off my finger, and instantly replacing it, more common, air rushes in, and the same phenomena recur. The process sometimes requires to be seven or eight times repeated, before the whole of the nitrous vapour (as I shall venture to call it) is condensed into nitrous acid, by the successive entrance of fresh parcels of common air after each effervescence; and the water becomes evidently more and more acid after every such fresh admission of the external air, which at length ceases to enter, when the whole of the vapour has been condensed. No agitation of the water is requisite, except a gentle motion, just sufficient to rince the sides of the phial, in order to wash off the condensed vapour.

The acidity which you (and I likewise, at first) observed in the water agitated with nitrous air alone, I account for thus. On bringing the phial to the mouth, the common air meeting with the nitrous vapour in the neck of the phial, condenses it, and impregnates the water with the acid, in the very act of receiving it upon the tongue. On stopping the mouth of the phial with my tongue for a short time and afterwards withdrawing it a very little, to suffer the common air to rush past it into the phial, the sensation of acidity has been sometimes intolerable: but taking a large gulph of the water at the same time, it has been found very slightly acid.—The following is one of the methods by which I have given water a very strong acid impregnation, by means of a mixture of nitrous and common air.

Into a small phial, containing only common air, I force a quantity of nitrous air at random, out of a bladder, and instantly clap my finger on the mouth of the bottle. I then immerse the neck of it into water, a small quantity of which I suffer to enter, which squirts into it with violence; and immediately replacing my finger, remove the phial. The water contained in it is already very acid, and it becomes more and more so (if a sufficient quantity of nitrous air was at first thrown in) on alternately stopping the mouth of the phial, and opening it, as often as fresh air will enter.

Since I wrote the above, I have frequently converted a small portion of water in an ounce phial into a weak Aqua fortis, by repeated mixtures of common and nitrous air; throwing in alternately the one or the other, according to the circumstances; that is, as long as there was a superabundance of nitrous air, suffering the common air to enter and condense it; and, when that was effected, forcing in more nitrous air from the bladder, to the common air which now predominated in the phial—and so alternately. I have wanted leisure, and conveniences, to carry on this process to its maximum, or to execute it in a different and better manner; but from what I have done, I think we may conclude that nitrous air consists principally of the nitrous acid, phlogisticated, or otherwise so modified, by a previous commenstruation with metals, inflammable spirits, &c. as to be reduced into a durably elastic vapour: and that, in order to deprive it of its elasticity, and restore it to its former state, an addition of common air is requisite, and, as I suspect, of water likewise, or some other fluid: as in the course of my few trials, I have not yet been able to condense it in a perfectly dry bottle.

NUMBER VI.

A Letter from Dr. Franklin.

Craven Street, April 10, 1774.

Dear Sir,

In compliance with your request, I have endeavoured to recollect the circumstances of the American experiments I formerly mentioned to you, of raising a flame on the surface of some waters there.

When I passed through New Jersey in 1764, I heard it several times mentioned, that by applying a lighted candle near the surface of some of their rivers, a sudden flame Would catch and spread on the water, continuing to burn for near half a minute. But the accounts I received were so imperfect that I could form no guess at the cause of such an effect, and rather doubted the truth of it. I had no opportunity of seeing the experiment; but calling to see a friend who happened to be just returned home from making it himself, I learned from him the manner of it; which was to choose a shallow place, where the bottom could be reached by a walking-stick, and was muddy; the mud was first to be stirred with the stick, and when a number of small bubbles began to arise from it, the candle was applied. The flame was so sudden and so strong, that it catched his ruffle and spoiled it, as I saw. New-Jersey having many pine-trees in different parts of it, I then imagined that something like a volatile oil of turpentine might be mixed with the waters from a pine-swamp, but this supposition did not quite satisfy me. I mentioned the fact to some philosophical friends on my return to England, but it was not much attended to. I suppose I was thought a little too credulous.

In 1765, the Reverend Dr. Chandler received a letter from Dr. Finley, President of the College in that province, relating the same experiment. It was read at the Royal Society, Nov. 21, of that year, but not printed in the Transactions; perhaps because it was thought too strange to be true, and some ridicule might be apprehended if any member should attempt to repeat it in order to ascertain or refute it. The following is a copy of that account.

"A worthy gentleman, who lives at a few miles distance, informed me that in a certain small cove of a mill-pond, near his house, he was surprized to see the surface of the water blaze like inflamed spirits. I soon after went to the place, and made the experiment with the same success. The bottom of the creek was muddy, and when stirred up, so as to cause a considerable curl on the surface, and a lighted candle held within two or three inches of it, the whole surface was in a blaze, as instantly as the vapour of warm inflammable spirits, and continued, when strongly agitated, for the space of several seconds. It was at first imagined to be peculiar to that place; but upon trial it was soon found, that such a bottom in other places exhibited the same phenomenon. The discovery was accidentally made by one belonging to the mill."

I have tried the experiment twice here in England, but without success. The first was in a slow running water with a muddy bottom. The second in a stagnant water at the bottom of a deep ditch. Being some time employed in stirring this water, I ascribed an intermitting fever, which seized me a few days after, to my breathing too much of that foul air which I stirred up from the bottom, and which I could not avoid while I stooped in endeavouring to kindle it.—The discoveries you have lately made of the manner in which inflammable air is in some cases produced, may throw light on this experiment, and explain its succeeding in some cases, and not in others. With the highest esteem and respect,

I am, Dear Sir,
Your most obedient humble servant,
B. Franklin.

NUMBER VII.

Extract of a Letter from Mr. Henry of Manchester.

It is with great pleasure I hear of your intended publication on air, and I beg leave to communicate to you an experiment or two which I lately made.

Dr. Percival had tried, without effect, to dissolve lead in water impregnated with fixed air. I however thought it probable, that the experiment might succeed with nitrous air. Into a quantity of water impregnated with it, I put several pieces of sheet-lead, and suffered them, after agitation, to continue immersed about two hours. A few drops of vol. tincture of sulphur changed the water to a deep orange colour, but not so deep as when the same tincture was added to a glass of the same water, into which one drop of a solution of sugar of lead had been instilled. The precipitates of both in the morning, were exactly of the same kind; and the water in which the lead had been infused all night, being again tried by the same test, gave signs of a still stronger saturnine impregnation—Whether the nitrous air acts as an acid on the lead, or in the same manner that fixed air dissolves iron, I do not pretend to determine. Syrup of violets added to the nitrous water became of a pale red, but on standing about an hour, grew of a turbid brown cast.

Though the nitrous acid is not often found, except produced by art, yet as there is a probability that nitre may be formed in the earth in large towns, and indeed fossile nitre has been actually found in such situations, it should be an additional caution against the use of leaden pumps.

I tried to dissolve mercury by the same means, but without success.

I am, with the most sincere esteem,
Dear Sir,
Your obliged and obedient servant,
Tho. Henry.

FINIS.

[15] See Dr. Falconer's very useful and ingenious treatise on the Bath water, 2d edit. p. 313.