j ' l%iJ£x3fi& ?*■> !&£» ' ?*■• NATIONAL LIBRARY OF MEDICINE Washington Founded 1836 U. S. Department of Health, Education, and Welfare Public Health SerTice cSfX «$, AN INAUGURAL DISSERTATION* SHEWING IN WHAT MANNER PESTILENTIAL VAPOURS Acquire their acid Quality, and how this is neutralized and deftroyed b$ ALKALIES. SUBMITTED TO THE PUBLIC EXAMINATION OF THE FACULTY OF PHYSIC, UNDER THE AUTHORITY OF THE TRUSTEES OF COLUMBIA COLLEGE, IN THE STATE OF NEW-YORK, WILLIAM SAMUEL JOHNSON, LL. D. President, FOR THE DEGREE OF DaC TOR OF PHYSIC, On the id Day of May, 1798. By ADOLPH C. LENT, Citizen of the'State of New-York. Gnomes! to impede the Demon's deadly courfe, Your bands celestial marfhaU'd all their force: From watery caves where fhelly nations fleep, From finuous bays, from Ocean's briny deep, Your hands collecting fpread thro' every clime, A fair proportion of attempering Lime; Thro' all the fpace terreftrial Nature owns, Of Climates, Colures, Longitudes and Zones, Your fearch the powerful Alkalis has found, And caft, the Earth^s circumference around; The friendly powers of Metal, Oil and Clay, With duteoUs zeal your juft commands obey; With wife difpatch their various {rations gain, And guard the Mine, the Mountain, and the Plain. MlTCHILtt NEW-YORK: ^ F.inted by T. & J. SWORDS, Printers to the Faculty of Phyfic of Columbia College, No. 99 Pearl-ftreet. -1798— V* *\ -■y INTRODUCTION. General Ideas of the Diforganization of Bodies after Death, XiXL animal and vegetable bodies, deprived of the principle of life, undergo certain changes, by which their texture becomes deftroyed, and their compofition altered; having loft the chemical affi- nity fubfifting between their elementary principles in their living ftate. The procefs by which this decompofition is effected, which renders more fimple the compounds formed by vegetation and animalization, and caufes them to enter into new combinations of different kinds, is named putre- faction, and is determined by the fame caufes, agents, and circumftances, in both, viz. oxygenous air, caloric, and water. Upon a proper application of thefe agents does the more rapid or flow diffolu- tion of thefe bodies depend. Animal fubftances, compofed of hydrogene, carbone, oxygene, and fep- ton (azote), and not unfrequently ftill more com- plex by the addition of fulphur, phofphorus, iron, lime, and foda, when deprived of that constitution which imparts to them life, and expofed to the in- fluence of thefe agents, are foon altered by more iimple attractions between their elements, which moft generally have a tendency to unite in binary \ ( 4 ..) or ternary combinations. This new aflbciation be-. tween their principles gives rife to new bodies, fuch as feptous (azotic) air, oxyd of fepton (azote), feptous acid, feptic gas, feptic acid* feptic acid gas, carbonic acid gas, hydrogenous gas, oxygenous gas, carbonated, fulphurated, and phofphorated hydro- genous gas, foda, water, and perhaps ammonia, which gradually efcape into the atmofphere, pro- portionally diminifhing the putrifying mafs. Upon the Union of thefe elements all the changes refult- ing from the putrefaction of animal bodies depend. In the union of fepton (azote) and oxygene, accord- ing as the acidifying principle unites with fepton in a greater or lefs quantity, we perceive the formation of feptous gas, and the oxyd of fepton, feptous and feptic acid, and feptic acid gas; to the pro- duction of which it is well known how much ani- mal fubftances contribute; as in nitre-beds, graves* ditches, puddles, &c. and in all thofe places where putrefaction takes place to any large amount. The combination of carbon and oxygene with caloric, explains the generation of carbonic acid gas. The carbon and hydrogene may unite in the form of fat, or that fubftance lb often defcribed as refembling fpermaaeti; and if ammonia is formed, it will pro- ceed from the union of fepton with hydrogene. It is poffible, alfo, in bodies containing fulphur and phosphorus, thefe acidifiable bafes may unite with oxygene, and form their refpective acids. Where lime (calcareous earth), foda, or iron, is extricated by putrefaction, thefe bafes may attach the carbonic, feptic, fulphuric, and phofphoric acids, and form ( 5 ) carbonates, feptites, fulphats, and pliofphates of lime, foda, and iron. Thefe-are the products, lia- ble, however, to variation, which are evolved on the putrefaction of animal fubftances. It may happen that all, or a greater part of the fepton, may com- bine with caloric, and fly off in this ftate in the form of feptous gas: on the contrary, all the fep- ton may unite with oxygene, and be converted into feptic acid. The fame variations may take place in the other combinations, according as the ele- mentary principles get within the fpheres of each other's attraction, and according to the varying proportions of the agents above enumerated. The products which obtain, on the deoompofi- tion of vegetables, are nearly the fame with thofe of animals; except that the compounds, into which fepton, fulphur, and phofphorus enter, are not fo often formed; nor are the feptic compounds pro- duced in fo great plenty, owing to a lefs quantity of fepton in the latter than in the former fubftan- ces;—the greater part of vegetables containing little or none, though others are furniihed plenti- fully with it. Vegetable fubftances, though liable to undergo diforganization, are not fo much fo as animal; their order of compofition being lefs com- plex : neither do they afford fo much feptous gas when acted upon by the feptic acid, nor contribute in fo eminent a degree to the formation of this acid. Thefe different appearances between the two fub- ftances, and the more rapid decay of animal bodies, feem to depend on the prefence of one elementary principle only, namely, fepton, being in a greater ( « ) abundance in animal than in vegetable fubftances, It appears probable, therefore, that by the addition of this principle to vegetable matter, it may be made to poffefs fimilar qualities with that of ani- mal ; and by depriving the latter of its fepton, it will become, in fome meafure, vegetable. This may be termed the capital difference between the two fubftances: but other phenomena, whofe in- fluence on the animal compofition is, no doubt, inferior, ought likewife to be noticed; fuch as the phofphoric acid, and its combinations with lime, ammonia, and foda; the quality of the refidue of animal matter, after diffolution, being principally owing to thefe combinations.* * yide Fourcroi's Philof. of Chemiftry, p. 16 3,163. ( i ; CHAPTER I. Relations of the Produtls of Animal and Vegetable Decompojition to other Bodies. ANIMAL and vegetable matter having been fhewn, on diffolution, to give rife to new com- pounds, fuch as the feptic oxyds and acids, &C and as all living fyftems, whether of plants or ani- mals, muft lofe the principle by which their life is continued, and become diforganized, the quantities of thofe gafeous fluids which are naturally formed and diffufed through the air in fuch proceffes, muft be immenfe, and exceed ordinary eftimation. From the perpetual accumulation of thefe gafeous bodies, it would feem the refpirability of the atmofphere muft, within a fhort period, become deftroyed, and, from the noxious and: even poifonous qualities of certain of thefe gafes, fuch as the feptic compounds, acquire a deleterious and deftructive operation on the conftitution of man, and other animals who live and move in it. This, from appearances, would really happen, were it not that thefe gafeous fub- ftances did again enter into union with certain other bodies, on coming within the fpheres of their at- tractions, by which they are taken out of circulation, and become fixed or decompounded. i. In this manner the oxyd and acid of fepton, on meeting with certain bodies, are taken out of circulation, and become fixed or neutralized, and thus reftrained from exe'rcifing; their deleterious ( 8 ) qualities, which, if left to pervade the atmofphere, would, on meeting the bodies of men, carry on their deftruCtive and corroding operation, and produce difeafes of different grades and malignancy, in pro- portion as the attendant circumftances, and the conftitution of each, were more or lefs favourable to their operation.—The principal of thofe bodies which have the power to .coerce and reftrain this acid, is pot-afh, or the vegetable alkali, alfo called fait of wormwood, and fait of tartar, with which the acid unites, and forms the feptite of pot-afh, commonly known by the name of falt-petre, or ni- tre, from which this acid has derived the name hi- therto moft commonly affixed to it, This faline fubftance, afforded by the combuftion of plants, has the ftrongeft attraction of all bodies prefent, where putrefaction takes place, for the feptic acid,* and will, confequently, difengage the acid from all other bodies with which it is united, and attract it itfelf.—There are certain foils and tracts of coun- try, as in Spain, Perfia, and the Eaft-Indies, where pot-afn is native, and by abfbrbing from putrid and all other bodies with which they meet, all the acid they contain, they change to feptite of pot-afh (nitre). Where this fubftance is not naturally pre- fent, it is frequently accumulated from adventi- tious circumftances; near the habitations of mert it is generally produced by the agency of fire; and large quantities of it, diffolved in water, are conti- nually thrown away with fuch folutions as have f Vide Bergman's Tab. of Elec. Attrac. J ( 9 ) been employed to aid common water in cleanfing, and anfwering the purpofes of wafhing.* In fuch inftances, where there is no pot-afh prefent, or there is more of the acid than it is capable to neu- tralize, it may be arretted by the muriate of foda (common or culinary fait), which is confumed in large quantities by men and brute animals. The alkaline bafis of the fait having a ftronper attrac- tion for the feptic than muriatic acid, it will dif- folve its connection with the latter, and form a union with the former, in the form of feptite of fo- da (cubic or quadrangular nitre). This acid like- wife unites readily with calcareous earth (lime), con- verting it into a feptite of lime (calcareous nitre). From the greater abundance in which lime is found in and about human dwellings, old walls, finks, drains, &c. than either of the above alkalies, it might be prefumed, that this acid, in conjunction with calcareous earth, would very commonly obtain. This is found to happen. The nitrous quality of old walls, plaiftered with lime, which takes place even to fuch an extent, as to have be- come worthy the attention of perfons engaged in the manufacturing of nitre, is fufficient evidence of the ftrong affinity which fubfifts between it and the acid; at the fame time proving this acid to be prefent within and around human dwellings, in confiderable quantity. Clay likewife has an affinity * See a calculation, made by Profeffor Mitchill, of the immenfe quantity of this alkali difiblved in water, which is, from time to time, thrown out in large and populous citits, in New-York Mag. for Janu- ary. 1797. P- 9- B ( IO ) for this acid; and in fuch walls where lime is one of the ingredients, and becomes faturated with the feptic acid, the clay will unite with.it, and be con- verted into an argillaceous feptite (aluminous nitre). Its affinity, however, is in fo weak a degree, that where either of the alkalies, or lime, is prefent, its union with the acid will be prevented, or diffolved, if made. This acid alfo unites wi^h the volatile alkali, for which, next to the fixed alkalies and lime, it has the greateft attraction; but from the rare occurrence of this alkali in the earth,' it will rarely happen that a feptite of ammonia is formed. Fat, or oily fubftances, will likewife unite with this acid, and that with fuch rapidity as to burft into flame with many kinds of oils^ " The action of the nitric (feptic) acid on molt inflammable mat- ters, confifts in nothing more than a continual de- compofition of this acid."—" The nitric (feptic) acid, when mixed with oils, renders them thick and black, converts them into charcoal, or inflames them, according as the acid is more or lefs concen- trated, or in greater or lefs quantity."* From the experiments of Margraff and other chemifts, this acid was alfo found in rain and fnow waters; and from the difpofition of water to enter into union with it, may it be learned how rain-water in fhowers acquires the unwholefome qualities which, in cer- tain inftances, it has been obferved to exert on the conftitution. ■ Hence, then, it appears, that the alkalies, calca- * Fourcroi, &c. Chaptal's. Chcmiftry, p. 133, &c, ( II ) reous earths, clay, oils, and water, on meeting the feptic acid, act in a beneficial manner, by repreffing and keeping down this fluid, which, by rifmg in the atmofphere, and pervading human dwellings, &c. might occafion intermittent, or other fevers of a more malignant or peftilential nature. 2. Carbonic acid (fixed air), which is fo plenti- fully formed during the putrefactive procefs from animal and vegetable bodies, by reafon of its greater fpecific gravity, never rifes to any great height in the air, but defcends to the furface of the earth, where it may either be abforbed by lime, or may contribute to the nourifhment of plants, which poffefs the power of decompounding and abforb- ing it, when in a fmall quantity.* 3 and 4. The hydrogene, or inflammable gas, that is fometimes extricated during putrefaction, efcapes, and mingles in the air with other gafes, with fome of which, more efpecially the oxygenous it may unite, and form water; while the oxygene gas that is fet loofe in certain inftances, may afcend and replenifh,inpart, the perpetual wafte which this fluid, from combuftion, refpiration, &c. muft necef- farily fuffer, from time to time, in the atmofphere. 5. The other gafeous compounds, to which the difagreeable fmell and phofphorefcent appearance attending vegetable and animal putrefaction are principally owing, may combine with certain bodies they meet with, or afcend in the atmofphere, from whence they may again be precipitated to the earth. * Chapt. Chem. vol. iii. p. 33. ( II ) CHAPTER II. Fails tending fofhew the Connexion between the Ef- fluvia of putrefying Bodies, and malignant andpef tilential Difeafes. FROM marfh exhalations and human effluvia, lias it been believed, from the earlieft ages of phy- fic to the prefent time, that malignant and peftilen- tial difeafes derived their origin. Daily experience ftill confirms that it is in the neighbourhood of marines, and all fuch places where vegetable and animal putrefaction takes place to any extent, that peftilential and other difeafes of various grades and violence prevail. Epidemics, attended with car- buncles and buboes, which are denominated, in con- junction with the ordinary fymptoms of what is called jail and hofpital fever, the charaCteriftics of the plague, down to the mildeft intermittent, have ap- peared, and raged with extreme violence, cccafioned by the exhalations from putrefying animal and ve- getable fubftances.* . The numerous facts and obfervations of the moft judicious writers friew, that there are few climates where inftances have not occurred of malignant epidemic and endemic difeafes, occafioned by an atmofphere furcharged and poifoned with.the ef- fluvia exhaled from certain putrid vegetable and animal fubftances. Bengal, on both fides the river Qanges, and Egypt, annually Overflowed by the *. Pringlc on the Army, p. 331 and 333. C *3 ) Nile, experience an unhealthy and peftilential at- mofphere, immediately after the exhalations from the putrefying collections of vegetable and animal matter begin to arife in the air, and bring on difeafes of various grades of malignancy, down to what is called the plague. The fame occurs in every cli- mate in a greater or lefs extent. In ponds, ditches, fwamps, &c. where, after the evaporation of the water, the collections of vegetable and animal mat- ter being left bare, and expofed to the influence of the fun, begin to putrefy, and emit certain gafeous exhalations, which transfufe themfelves into the at- mofphere, and produce difeafes of an intermittent or more malignant type, proportionate to the con- centrated ftate of the contagion, and other conco- mitant circumftances. Lind, whofe teftimony, from his experience, muft equal moft authors, re- lates abundance of inftances where what is called yellow fever, and other-*malignant difeafes, were caufed by gafeous fluids, exhaled from low and marfhy places, expofed to the influence of a pow- erful fun. He obferves, that " in all fpots, in the Eaft-Indies, fituated near large fwamps, or the mud- dy banks of rivers, or the foul fhores of the fea, the vapours exhaling from putrid ftagnated water, from the corrupted vegetable, and other impurities, pro- duce mortal difeafes."* The fame author more particularly mentions, that the yellow fever often raged at Greenwich Hofpital, in Jamaica, which, he obferves, was built near a marfh, and could not • Lind on Hot Climates, p. 85. ( h ; proceed from any fource of infection in the hofpital. He every where attributes the yellow fever to the vapours arifing from putrefying vegetable and ani- mal fubftances. Dr. Clark, in his Obfervations on the Difeafes of lon<>- Voyages to hot Countries,* mentions a con- tagious malignant fever, which prevailed at Prince's Ifland, in 1771, produced from the exhalations of putrefying vegetable fubftances. The plague which caufed fo great a terror and mortality in London, in 1625 and 1636, according to the account given by Mr. Woodal, furgeon to St. Bartholomew's Hofpital, and furgeon-general to the Eaft-India Company, who was prefent thofe •two years during its prevalence, was evidently gene- rated in that city, from the gafeous exhalations of putrid collections of animal and vegetable matter. He fays, " the terreftrial caufes (after mentioning it as a punifhment inflicted on mankind for their fins,) are, by common confent of molt writers,* as followeth; venomous and ftinking vapours, arifing from Handing ponds, or pooles, ditches, lakes, dunghills, finks, channels, vaults, or the like; as alfo unclean flaughter-houfes of beafts, dead car- cafes of men, as in time of war, and of ftinking fifh, fowl, or any thing that hath contained life and is putrid: as alfo, more particularly in great cities, as in London, the unclean keeping of houfes, lanes, alleys, and ftreets: from thofe recited, and the like infectious venomous vapours, by warmth of the * Vol. i. p. 123 and 124. ( '5 ) (un exhaled, are apt and able to infect the living bo- dies of men, and thereby to produce the plague, as experience too much fheweth."* From the de- fcription given by Meadf of Grand-Cairo, the fup- pofed harbinger of a fpecies of the worft type of dif- eafe, the plague, it will appear to be produced by fimilar caufes with the above cafe, viz. by certain gafes formed on the putrefaction of vegetable and animal fubftances, and fuffered to arife into and poifon the circumambient atmofphere with their noxious and ftimulating qualities. He fays, " it is fituated in a fandy plain, at a foot of a mountain, which, by keeping off the winds that would refrefh the air, makes the heat very ftiflirig. Through the midft of it paflfes a canal, which is filled with water during the overflowing of the Nile, and, after the river is decreafed, it gradually dries up. Into this canal the people throw all kinds of filth, carrion, &c. fo that the ftench arifing from it, and the mud to- gether, is infufferable. In this fituation of things, the plague every year conftantly preys upon tile in- habitants, and is only ftopt when, the Nile, by over- flowing, wafhes away the load of filth." Pringle, Jackfon, Hume, and a number of other authors, might be added in further proof, that the effluvia from animal and vegetable putrefaction may give rife to, and are the common caufes of ma- lignant ^nd peftilential difeafes. Inftances, abun- dantly numerous, occur in our own territory, to confirm the noxious and peftilential influence of * Monro on the Army, vol. i. note to p. 123. f On the Plague, p. 29 and 30. ( '6 ) the products juft named, on their application to the conftitution, notwithstanding the (fo named) fails, which were promifed fpeedily to appear almoft a year fmce, in contradiction of this opinion. It is related by Dr. Reynolds,* that from the putrefaction of a horfe, which lay on the borders of a marfhy piece of ground; a young woman who lived near, and was obliged frequently to pafs and repafs the putrid car- cafe, was affected with violent pains in the head, and ficknefs at her ftomach. On the fecond day of attack was bled, but her fever increafed, and the became delirious. A number of blifters, furround- ed by inflammation, appeared upon her feet and hands, fingers and toes; and fhe died the fourth day. A cafe, a few years fince, occurred in this city, where a fevere attack of fever, of the remittent type, attended with petechias, made its appearance in two perfons of the fame family. On examination into the caufe of thefe complaints, it was difcovered, by the attending phyfician, to have originated from the blood and other offal of cattle, Slaughtered in the yard belonging to the houfe, which was fuffered to collect and putrefy, to the exhalations of which the two perfons attacked had been, from time to time, expofed. An inftance of a fimilar nature, which occurred to a practitioner of a neighbouring town, is related by Mr. Bayley, in his treatife on the epi- demic of New-York in 1795.^ " Some time in the month of September I was called to vifit a young-man about eighteen years old, in a family in * Webfcer's Collection, p. 19? f P. 84 & feci. ( >7 ) the fkirt of the (Hartford) town. He was violently attacked with moft of the characteristic fymptoms of yellow fever, &c. The next day a fecond was taken in the fame manner; and, on the morning of the third, three more were taken fick. This led me to fufpeCt fome particular caufe. I fearched for it in vain that time. The next morning, on paffing through the kitchen, I fmelt fomething that was very offenfive, which none of the family had no- ticed. On opening the cellarrdoor, I found that it proceeded from the cellar. Two perfons went down to examine, and found, in one corner of a fmall tight room, a quantity of June cabbages, on which the fun had (hone about three hours in a day. They had rotted, and funk down in a lump of pu- trefaction, They run a ftick under them, and lift- ed them up, and there immediately iffued fuch an intolerable Stench, as obliged them inftantly to leave the cellar. A vomiting was brought on at once, which lafted them nearly an hour. Notwith- standing that the doors and windows of the cellar were thrown open, it was two days before they could clear it out. No other perfon in the family was taken afterwards, and thofe who were already feized foon recovered," The malignant epidemic, or yellow fever, which prevailed, in the Summer of 1797, in Providence, Rhode-Ifland; in 1795, in Norfolk, Virginia;* and, in 1791, in New-York, evidently took their origin from gafes exhaled from vegetable and anir * Webfter's Collection, p. 148 * fe^. c I <8 ] mal fubftances, fuffered to collect and putrefy, on expofure to a heated atmofphere. It would be end- lefs and unneceflfary to add facts in further confirma- tion of the noxious and deleterious qualities of cer- tain gafes, formed from vegetable and animal pu- trefaction, on its application to the constitution. Thofe already related, as well as various other in- ftances, Sufficiently confirm, that the greatest de- gree of vitiation which the atmofphere manifests by its operation upon the constitution, proceeds from the effluvia emitted from certain vegetable and animal fubftances during putrefaction. And, as far as the innumerable facts on this Subject have been collected and examined, there exifts the moft co- gent evidence, that the products juft named form infection, or contagion, marfh-miafmata, or human effluvia, or whatever other name has been affixed to it. What the precife nature of thefe exhalations, or caufe of fevers, was, and which the particular noxious gas, though long a fubject of inquiry, re- mained unknown, till, within a few years fince, Mitchill, Profeffor of Chemiftry, Natural History, and Agriculture, &c. in Columbia College, engaged in an investigation of its properties, made known to the world what that poifonous fomething, which is formed during animal and certain vegetable pu- trefaction, was. He difcovered it to be a portion of fepton (azote), one of the elements of the body undergoing putrefaction, united chemically with more or lefs of oxygene (the acidifying principle), in the form of feptic (nitric) oxyd and acid.* On * Vide Mitchill on Contagion. ( *9 ) the formation and prefence of this compound, it is prefumed, do peftilential and other malignant dif- eafes depend. And, in proportion as a greater Cr lefs quantity of the above compound is formed; in proportion to its fparfe or concentrated State; in proportion to the length of time, the fufceptibility of the constitution to be operated upon, and the circumftances tinder which it is applied; will the difeafes, depending upon this caufe, be more or lefs violent, and attended with various peftilential Symptoms, CHAPTER III. Inquiry into the Hiftory, Production, and Qualities, of that Acid which attends the Putrefatlion of fuch Bodies as give Rife to malignant and peflilential Difeafes. SEPTON, the bafe of the acid of putrefaction, or feptic acid, is one of the moft abundant elements in nature: it has not hitherto been fubjected to any exa- mination by itfelf, as no experiments have been able to detect it in a diftinct and feparate State. In com- bination with caloric (the matter of heat,) it forms feptous (azotic) gas, which compofes nearly three fourths of our atmofphere, and is the fame Species of air which living plants are fuppofed to exhale in the night, according to Ingenhouz.* It likewife • % Experiences fur, &c. feci. vii. ( u ) Constitutes one of the elementary principles of cer- tain plants : and, from the refult of certain expe- riments made by Eagleton Smith, Efq.* appears to be one of the elements which compofe animal poifons, as was* fome time previous to this, prefumed by Profeffor Mitchill. From the Similar action on animals, of fuch animal poifons as were ufed by the experimentor, Such as that of bees* ants, and fome other infeCts, with the decoction of the poifonous plants, laurel, tobacco, digitalis* opium, &c. it ap- pears highly probable, that their deleterious qua- lities are owing to a modification of this fame prin- ciple, viz* feptom It alfo enters largely into the compofition of the mufcular fibre* blood, and lean parts of animals, in combination with carbone, hy- drogene* and phofphorus, which are united together by a certain portion of oxygene* forming animal oxyds and acids* in proportion to the degree of oxy- genation. This gas, in its pure and distinct form, is incapable to mppoft refpiration and combuftion * while it Sustains the life of plants* which appear to poffefs the power of decompounding it, and to at- tach to themfelves the fepton, which enters into and constitutes one of their principles.*!* This prin- ciple, or element, is alfo capable of uniting with oxygene, the principle of acidity* forming with it, in proportion to the quantity of this laft fubftance, i. The gafeous oxyd of fepton (dephlogifticated ni- trous air); 2. Septic (nitrous) gas; 3 and 4. Septous * Vide Appendix A. f Mitchill on Manures. Med. Repof. vol. i. No. I. ( 21 ) and feptic (nitrous and nitric) acids; and, 5. Sep- tic acid gas. 1. In the firft of thefe forms, that of the gafeous oxyd, in which the acidifying principle is fo fmali as not to manifest the fmalleft degree of acidity, it is capable of Supporting combuftion, but is highly deleterious to the lives of animals, which it deftroys the moment they are furrounded by an atmofphere of this kind.* 2 and 3. The next degree of com- bination of oxygene with fepton, is the feptic gas, and the feptous acid. Thefe are artificial produc- tions, and never found to exift in the atmofphere for any confiderable length of time, as their exist- ence depends on being kept clofed, and free from contact with the air. The rapidity with which they abforb oxygene from the atmofphere, on ex- pofure, is fo great as to become quickly faturated with this principle, and turn to feptic acid. As their existence in the air is only momentary, unlefs kept from coming in contact with it, they can have no material influence on man or brute animals; and their qualities are fo widely different from thofe of the more highly oxygenated form, the experiments and conclufions drawn from the two former, cannot apply to account for the phenomena of the latter. 4 and 5. The feptic acid, which is Still higher dofed with oxygene, and the feptic acid gas, the highefl degree of oxygenation of fepton, the form in which thefe compounds molt commonly exift, and which are produced wherever fepton and oxygene • Prieftley on Air, vol. ii. p. z$. ( « ) come into chemical union, have, for a length of time, been confidered of mineral origin, and claffed among the acids of this kingdom. How far this opinion is founded in experience, and deduced from facts, will appear on examination of the ma- terials, and fources, from whence it is derived. It is well known that nitre confifts oS feptic acid joined to pot-afh, and is ufually formed during the decay of animal and fuch vegetable bodies as contain fep- ton. And it is afcertained, that fepton and oxy- gene enter into the compofition of thofe fubftances, when alive, and have gone into new combinations, on their difengagement, after death. One of thefe recent compounds muft be feptous and feptic acid, constituting, by junction with a faline bafe, the fep- tite of pot-afh. The theory, of faltrpetre thus ne- ceSTarily prefumes the generation of feptous and feptic acid, from two of the elements difengaged from organic texture. And as fepton, the radi- cal of the acid, is efpecially abundant in animal bodies, there is little difficulty in comprehending both how, in fuch circumftances, it attracts the acidifying principle, and afterwards attaches itfelf to the alkali. Nicholfon obferves it to be well known, that the feptous acid, inftead of existing in the mineral kingdom, is almoft always produced by a concurrence of circumftances, chiefly confift- ing in the expofure of putrefying fubftances to the atmofphere; and that it is formed by the union of two principles, which are always found in atmof- pheric air, and the exhalations of putrefying fub- ( 23 ) Stances.* The nitrous quality of the earths at the bottom of graves, in which animal diforganization has taken place, is further testimony of the origin of this acid, as in this cafe it could not have ac- quired its feptic quality from any other fouree. Hence may be understood how other earths, fuch as thofe of Stables, cow-houfes, cellars, vaults, drains, finks, &c. &c. acquire their nitrous quality. Dur- ing the putrefactive procefs of fuch vegetable bo- dies as contain fepton, and animal matter, which abounds in this principle, the oxygene derived ei- ther from the corrupting bodies themfelves, from the water in or near them, or from the atmofphere, unites with this principle, and forms the feptic acid, which, being taken up by thefe earths, converts them into nitrous foils. In further confirmation of the origin of this acid, may be added the authority of Fourcroi, who fays, a It is no longer to be doubted that the falt-petre, which forms itfelf under our eyes, in foils foaked by vegetable and animal juices, or in Stones impreg- nated with the fame juices, or their vapour, (the materials which compofe the floors and walls of our Stables, vaults, &c.) reprefent, in this refpect, real artificial nitre-beds."-f- This acid is alfo found to exift occasionally in the atmofphere. The experiments of Margraff^ on fnow and rain-water, and Bergman's analyfis of waters, prove its prefence in the air, from whence * Nicholfon's Chemiftry, p. 32. f Vide Med. Repof. vol. i. No. I. p. 71. $ Vide Watfon's Chem. Effaye, vol. ii. p. 70. ( *4 1 they are precipitated By thefe bodies, and mix with them in their defcent. The nitrous quality of the calcareous matter of old walls, which takes place to fuch an extent as to be converted to economical purpofes, affords like proof ©f its prefence in the at- mofphere. The bafes of the two gafes, fepton and oxygene, which compofe this acid, constitute likewife our at- mofphere, but in different proportions and com-* binations. The feptic acid is found to contain four parts of oxygene and one of fepton, chemically united; while the proportion of thefe ingredients in atmofpheric air about the mean ratio, are 27 of the former to 73 of the latter; not, however, chemi- cally united, but only diffufed through each other, as clay is diffufed through water, or as motes are feen paffing through fun-beams. Thefe gafeous components of the atmofphere are intimately blend- ed, and mixed together, but do not lofe their at- traction for caloric, by which they are continued in this ftate, and for which, in ordinary circumftances, they have a greater affinity feparately than for each other. It is by virtue of this attraction for the matter of heat, that they are each kept in a State of gas, and not Suffered to unite, and form feptic acid, and thereby deftroy the refpirability of the atmof, phere. Dr. Beddoes remarks, that " the nice balance of attraction between the constituent parts of the at- mofphere deferves notice. Thefe two fubftances, when clofely united, form nitrous (feptous) acid; if, therefore, they were not, by fome circumftances, ( is ) prevented from uniting clofely, all the oxygene, with part of the azote (fepton), would be changed into a highly concentrated acid, and the waters of our globe would be converted into aqua-fortis," (fep- tous acid).* Fourcroi alfo obferves, " that this (feptic) acid is compofed of the fame elements with atmofpheric air, only under a different form, and in different proportions, Srom thofe which constitute the atmofphere, Thefe facts are indifputably efta- blifhed by experiments in which the nitric (feptic) acid is decompofed, and again produced by the union of the original elements. Hence it is de- monstrated, that it confifts of four parts of oxygene, and one of azote (fepton). But thefe two princi- ples, as contributing to the formation of the atmof- phere, are in the proportion of a little more than two parts and one half of the firft, and one of the fecond, and exift in an uncombined ftate, feparately diffolved in a common menftruum, and without the poffibility of contracting a real chemical union. Hence it arifes, that atmofpheric air is never fpon,- taneoufly converted into nitric (feptic) acid."-f The formation of feptic acid in the atmofphere feems, however, to take place under certain circum- ftances ; as when the two constituent elements of the acid are brought into clofe union, and within the fphere of each other's attraction, by fome violent concuffions, fuch as lightning in thunder-ftorms. The experiments made by Mr. Cavendifh,J who, * Confederations on the Medicinal Ufe, and on the Productions, of Fac- titious Airs, p. 18. t Vide Med. Repof. vol. i. No. r. p. 68 and 69. J Chaptal's Chem. vol i. p. 319. D ( *6 ) by pafling the electric fpark through a portion of oxygenous and feptous (azotic) gafes, obtained this acid, further tends to corroborate this opinion, and leads, at leaft, to a belief, that this procefs, to a larger amount, is constantly taking place in the up- per regions of our atmofphere, by the intervention of the electric matter. CHAPTER IV. Atlion of this Acid and its Oxyds upon Timber, Me- tals, Earths, alkaline Salts, and Water. THE feptic acid having been fliewn, in the pre- ceding chapter, to owe its origin to animal and ve- getable decompofition, its operation on timber, metals, &c. will next be considered. Facts, fufficiently numerous, prove that this acid, generated by putrefaction, is always on or near the furface of the earth, and from thence, when ex- isting in any confiderable quantity, pervades the atmofphere, and, on meeting with certain bodies, unites with them, and becomes fixed or decom- pounded. If, in its vaporific form, it, meets with the woody portion of dwellings, around and in which it is more or lefs plentifully evolved, more eSpecially the unclean, there can be no doubt but a quantity of this acid is imbibed, as all thefe ma- terials are porous in a greater or lefs degree. There are no direct experiments, however, which prove ( *7 ) that there exifts a chemical union between the acid and it; but, from the readinefs with which wood is penetrated by water, and the known union which this latter body poffefles for contagion, it muft not unfrequently be conveyed in this manner, and com- bined with the timber of human habitations, where thefe gafeous vapours, extricated during vegetable and animal putrefaction, abound: the quantity taken up will, in all probability, be proportionate to the porofity of their texture; and in this ratio may the different kinds of wood be capable of im- bibing the acid. The rapid decay and rotting of the timber of fuch veflels as carry wheat, is further testimony of the union and destructive operation of this acid, on its application to wood. The man- ner in which this procefs takes place, appears to be owing to the grain falling through the flooring of the veffel, where, on mixing with the water there commonly prefent, putrefies. Wheat, containing the principle of putrefaction in no fmall quantity, has, during its diffolution, this principle, united with a Sufficiency of the oxy- gene, Supplied either by the water, or what it itfelf contained, to form the feptic acid, which, Spread- ing itfelf, attaches and unites with the timber, caufing it to rot and decay, more or lefs rapidly, in proportion to the Strength and activity which the acid attains. From this difpofition of the acid of putrefaction to combine and unite with the woody portions of dwellings, Ships, or whatever elfe it comes in con- tact with, may it happen, that the noxious matter,- ( *8 ) faid, in fome veflels, to infect each fuccefhve crew, derives its poifon. 2. The operation of the feptic acid, as above ob- ferved, in rotting and breaking down the timber of veffels, has been noticed to ruft and corrode, pro- portionally quick, fuch iron fpikes and nails as were expofed, in a Similar manner, to the fame caufe; and, from its corrofive qualities, gradually deftroys and wears them away, if prefent in fufficient quan- tity, till nothing but ruft is left remaining. Such inftances as have been collected and examined on this Subject, go to prove this operation of the acid on metals. It has been obferved, that in the Weft- India Iflands, where putrefaction goes on rapidly, fuch iron cannon as were expofed to the atmofphere, commonly Surcharged more or lefs with this acid, rufted much Sooner than thofe which had been bu- ried in the fand in fait water. The teftimony of Van Sweiten alfo corroborates the activity and de- structive influence of this acid on metallic bodies. He mentions, that at Oczakow, during the plague, " the instruments made ufe of by the furgeons turned as black and livid as if they had been dip- ped in aqua-for tis," (feptous acid)—and " the Sil- ver hilt of a fword, which, all the time of the plague, hungup in a tent, was changed quite black." 3. The action of this acid, in refpect to earths, is more obferved, and takes place to a larger extent. Ii: readily unites with calcareous earth (lime), when- ever they come within chemical attraction, in the form of a feptite of the fame, (calcareous nitre,) as appears from the nitrous quality of old walls of ( *9 ) privies, finks, drains, &c. Grounds frequently trod- den by cattle, and impregnated with their excre- ments, the walls of Slaughter-houfes, and the like, where exhalations from putrid animal and vegeta- ble fubftances abound, as well as the formation of nitrous earths at the bottom of graves in which ani- mal bodies have decayed, puts it beyond difpute, that thefe earths have an attraction for and unite v with this acid. This affinity between the acid of putrefaction and lime, takes place to a greater or lefs extent in every habitation, more efpecially in large and crowded cities, where the Strictest atten- tion is not paid to remove all filth, and putrefying animal and vegetable materials. • It was fo well known, as to become an object worthy the atten- tion of a body corporate in Paris, who obtained li- cence to take away as much of the old mortar of the walls of houfes, torn down, as they pleafed, for the exprefs purpofe of making nitre, Hence may be learned the quantities of feptic poifon that is prefent, and floats about the habitations of man, gradually undermining his constitution, and cauf- ing malignant difeafes, if not taken, out of circula- tion, and combined with fome fubftance.. 4. This acid likewife, on meeting with the car- bonates of alkaline falts, decompofes them, by de- stroying the chemical affinity fubfifting between them and the weaker acids; while, at the fame time, it attaches to itfelf the alkaline bafis, forming with it a feptite of the fame. The facts already quoted, in the firft chapter, put it beyond doubt, that the acid of putrefaction readily unites with ( 3° pot-afh, foda, and ammonia, refpectively, in the form of feptites, wherever they come within the Sphere of each other's attraction: and, if it is evi- dent that thefe bodies enter into combination, there will be no difficulty to Shew, that this acid likewife unites with ftich falts as have an alkali for their bafe. According to Bergman's tables of elective attrac- tions, the feptic (nitric) acid has a greater affinity for pot-afh than for any other alkali; and that no acid but the fulphuric will diffolve their union.* On coming, therefore, in contact with fuch falts as have this alkali for their bafis, it will decompofe them, and, from its fuperior affinity for this latter fubftance, combine with it in the form of a feptite of pot-afh.. In the fame manner will thofe falts, having foda and ammonia for their bafis, be operat- ed upon by this acid. 5. The prefence of this acid in water, and its ready and entire mifcibility with this body, is evi- dent from the experiments made, with the utmofe diligence and attention, by Bergman and other che- mists, on rain and fnow water. The teftimony of Lewis is further confirmation of this union between the two bodies. He obferves, that " common wa- ters, both atmofpherical and Subterraneous, contain a little of this acid in combination with it ;"-j- and * Although the feptic acid does not poffefs an attraction for either of the alkalies, in fo eminent a degree as the fulphuric, according to Berg- man's tables cf elective attractions, yet, from his note, it appears it is capable to difengage the fulphuric acid, in fome cafes, partially, from its connection with alkalies, though not fo rapid and entirely as either oi the other acids. f Materia Medica, vol. ii. p. 120. ( 3V ) that among the fubftances commonly found in wa- ters, is the " nitrous (feptous) acid, combined with an alkali into nitre, or with fome of the foluble earths into nitrous falts."* " The pureft of the common waters is that of fnow; and the faline mat- ter of this kind of water is commonly of the nitrous kind, compofed of the acid of nitre (feptic acid)* united with calcareous earth." It is agreed upon by almoft all obfervers, that the vapours from Stagnant waters do feldom occa- fion much mifchief, as long as the mud and flime remain covered. The reafon of this is obvioufly owing to the mud, while covered by the waterj emitting its poifon but Slowly, which, as it arifes to the furface, mixes with the incumbent water, and remains united with it, fo that little or none efcapes to taint the atmofphere. But at length, as evaporation goes on, and the water is nearly eva- porated, thefe fluids, rarefied by heat, and becom- ing volatile, afcend into the atmofphere, and taint it with their noxious qualities, to the detriment of man and brute animals, who live and move in it. On this mifcibility of feptic, or acid of putrefac- tion, with water, no doubt, does it happen, that Showers of rain, as obferved by almoft every writer on the difeafes of hot climates, poffefs fuch bene- ficial and falutary effeCts. The rain, in its defcent, meets with this acid, unites with it, and thus pre- cipitates it again to the earth, leaving the atmof- phere in a ftate freed from its poifon. In theiame r Vol. i. p. 118. ( 3* ) manner may dews and fogs, in their defcent, unite with this acid vapour; and to the gradual and flow precipitation of water from the air* falling through this infectious fluid, and carrying a portion of con- tagion along with it, does it happen, that the crews of veffels, fent on fhore, and Sleeping on or near the furface of the earth, in the open air, in fuch places where thefe peftilential vapours abound, are fo com- monly feized with difeafes which deftroy their lives. The natives of the Eaft-Indies are fo well aware of the noxious qualities, at times, of rain-water, which falls firft in Showers, that they are cautious how they expofe themfelves to it. As evidence of this atmofpherical water containing fomething delete- rious, it has been known to caufe foal-leather to become mouldy and rotten in the fpace of forty- eight hours. The fame was alfo obferved to hap- pen in our own city, in the time of the epidemic, in 1795. Hunter alfo remarks, that expofure to rain is believed to be thecaufe of fevers in the ifland of Jamaica. The practice among Europeans at Con- stantinople, Grand-Cairo, and other places where the plague rages, to cleanfe all their goods, &c. they receive by means of water, is further corrobo- ration that peftilential gas unites with water, info- much that thefe bodies, thus cleanfed, are deprived of communicating any poifon they had previously imbibed. To this mifcibility of contagious fluids with water, may cold bathing, in malignant dif- eafes, owe its beneficial and falutary effects—the poifon which adhered to the fkin and its pores being I 33 ) thereby conveyed off, and rendered harmlefs to the constitution. From the preceding facts, then, it may be con- cluded, that the feptic acid, generated in all filthy and unclean dwellings, finks, &c. on meeting with either of the fubftances above enumerated, unites with them, becomes fixed or decompounded, and thus taken out of circulation. By this wife provi- lion of nature, the acid of putrefaction, which muft be formed in no fmall quantity, confidering the immenfe and incalculable mafs of vegetable and animal matter which is continually undergoing dif- organization, is arretted and restrained from affum- ing its corrofive, Stimulant, and poifonous qualities, which it exerts on man and brute animals, when fet loofe in the atmofphere. CHAPTER V. Effetls produced by it upon the Conji'itution of Men, particularly the Month, Throat, Alimentary Canal, exterior and pulmonic Surface, Heart, Blood-vef- fels, and Lymphatic Syftem. HAVING afcertained, as it is hoped, the caufe of moft endemic and epidemic difeafes, the fources of their origin and formation* together with their affinities and action on different bodies; their ef- fects on the living constitution Shall next be confi- dered. K ( 34 ) i and 2. The effects of oxyds and acids of this fort, when applied to the living body, which, in fome inftances, may be completely furrounded by an atmofphere^ highly charged with thefe gafeous fluids, are inflammations or ulcerations, together with many other difeafes of different kinds; and, if infpired in a concentrated ftate, may caufe in- stantaneous death. On its application to the fau- ces and throat, from its cauftic and corroding na- ture, it may inflame, and excite heat and diftreffing pain in the Surrounding parts, and bring on apthse, and erythematic affections of the pharynx and sefo- phagus, as is obferved to happen under certain cir- cumftances where it is generated, or prefent, from any other caufe,'in fufficient quantity. The expe- riments of Profeflbr Mitchill,* in his courfe of lec- tures, in 1796, on the tartar of the teeth, Shews that this acid may be (and is occasionally prefent in the mouth) either formed from the remains of corrupt- ing food, or taken in, by inspiration, with atmof- pheric air. This operation and effect, produced by the acid and its oxyd, on the fauces and throat, is further confirmed by facts of difeafes of thefe parts, induced by breathing air highly vitiated with pef- tilential effluvia. To this effect is the obfervation of Huxham, who remarks, that " for many months paft we had fcarce the Slightest fever, but it was at- tended with fore-throat, aptha?, and fome kind of cuticular eruption, and that, too, in pleuritic and pneumonic diforders; fo greatly did the conftitu- * Vide Mitchill's letter to Thomas Charles Hope, M. D. in the New York Mag. for February, 1797. ( IS ) tion of the air, &c. feem difpofed to produce erup- tions in all forts of feyerifh indifpofitions."* Robertfon, in his remarks on the Monthly Re- view of the lick in July and May, alfo obferves, that to the clafs of fever, the dyfenteric belly-ache, and almoft all the cough and fore-throat cafes, fhould be added, becaufe they originated, I had nearly faid, from the fame fource; thefe different appearances depending on the habits or constitu- tions of the Subjects infected."-j~ In the peftilential fever which prevailed at Win- chef ter Hofpital, many were feized with uneafinefs of Swallowing, and complained of a forenefs of the throat.]; To this may be added the authority of Chifholm, who, in his account of an epidemic fe- ver in Grenada, remarks, among other obfervations, that " fome complained of a rawnefs, as it were, from the throat to the Stomach;" or, as they ex- preffed it, " a rawnefs and burning of their in- war ds."§ Hence, then, it will appear, that this volatile acid does occafionally enter the fauces, and extends its influence to the aefophagus, caufing a greater or lefs degree of inflammation and uneafinefs in the parts, according as the poifon is in a more or lefs concentrated form, and to the length of time it is applied. The mucus which lubricates the parts, and is continually excreted in confiderable quanti- * On Fevers, p. a74. f On Jail Fevers, p. 325. J Smyth on Jail Fever, p. la. § Med. Com. for 1791, p. 267. ( 36 ) ties, more efpecially on the introduction of any ex-i traneous body, may, in all probability, defend them from more repeated attacks of this acid, by uniting with, and preventing its coming in contact with the parts. 3. The operation of this acid on the Stomach and inteftines appears more frequent than the above, and is productive of greater evils and fatality to the constitution. It may be either taken into the ftomach by mixing with the faliva, and fwallowed, or may be generated in the inteftinal canal, on the putrefac- tion of fome of thofe fubftances that are taken in for our nourifhment. The opinions of the moft re- SpeCtable authorities countenance thefe modes of operation. The faliva and fluids of the mouth confift principally of water, and may, therefore, be fuppofed to poffefs an attraction for thefe conta- gious gafes. The infection, thus finding its way i%to the mouth, will almpft unavoidably get into the ftomach during the deglutition of our food, or be conveyed there with our drink. Balfour, in a Treatife on Putrid Inteftinal Re- mitting Fevers, afcribes the caufes of thefe com- plaints to a putrid ftate of the mucus lining the intef- tines, which, being abforbed by the lacteal veffels, and carried into the blood, caufes the febrile Slate. —" This mucus receives the infection firft by con- tagious matter taken into the ftomach by means of the faliva."* To this may be added the authorities of Turner, * P*gc 130. ( 37 ) Gardiner, and Lind 4 the latter of whom fays, that fwallowing the fpittle, m infected places, is juftly deemed a means of fooner acquiring the taint; for which reafon neither the nurfes, nor any one elfe, fhould be fuffered to eat in infected hofpitals. " I am apt to think, that infection, from whatever im- pure fountain it is derived, does firft difcover itfelf by affecting the ftomach and inteftines."* Another mode in which the difeafes depending on the feptic acid are generated, is by the putrefac- tion of thofe fubftances taken into the ftomach, from time to time, for our fupport. If it is evi- dent, that animal and vegetable matter, undergo- ing diffolution in the open air, give rife to the fep- tic acid and its oxyds, is it not prefumable, that this fame compound will be formed, on the cor- ruption of fimilar fubftances, in the prima via o'f human bodies ? It is neceffary to the maintenance of life, that a proper quantity of food be taken into the ftomach, from time to time; and that the di- geftive organs perform their functions properly; for, as the diet is principally of the animal kind, and, confequently, containing all the elements ne- ceffary to the formation of the feptic compounds, it would undergo putrefaction in the inteftinal ca- nal, were it not prevented by the faliva, gaftric li- quor, pancreatic juice, and bile, which, mixing with it, diffolve and prepare it for the varioqs pur- pofes it is intended to anfwer. As long, then, as the'Stomach fecretes its liquors in healthy and due * On Hot Climates, p. 65. ( 38 ) quantities, will its contents be kept in utter impof- iibility of forming the feptic poifon. But when thefe preventatives are entirely fufpended, or weak- ened, from debilitating caufes, fuch as the too libe- ral ufe of fpirituous liquors, exceffive heat, fatigue, or from any other procefs by which its healthy func- tions are deftroyed or impaired, then it is evident that the food will be liable to corrupt, and the products formed from thefe materials, within the ftomach and inteftines, fimilar to thofe which ob- tain without the body. A fource of poifonous ef: fluvia feems thus to exift in our bodies ; and, from its Stimulant qualities, the occurrence of naufea, burning pain, and exceflive vomiting, together with other fymptoms of gaftretis, will not be difficult of explanation. To this caufe, whether generated in the prima via, or taken in from a vitiated atmof- phere, when applied to the inteftinal canal, are di- arrhoeas, dyfenteries, and cholera morbus, difeafes of the fame genus, only differently modified, refera- ble. The inflamed State of the ftomach, duode- num, and lower parts of the inteftinal canal, and the black gangrenous and mortified fpots, are all owing to the operation of this acid, which, in fome cafes, may acquire a higher degree of malignancy than common, by uniting with a larger portion of cxygene. The coffee-coloured matter, commonly called black vomit, ejected in what are called bilious remitting fevers, feems to owe its colour to a mixture of this acid, as appears from its Stimulant nature, noticedby diffectors, with a quantity of bile and blood, which is poured out of fuch veffels as have ( 39 ) their coats deftroyed by this poifon. That this is not a difcharge of putrid bile, is evident from the experiments of Saunders, who obferved, that fo far from its becoming putrid, it was lefs liable to undergo this procefs than any other of the animal fluids, arid would even prevent the diforganization of fuch fubftances as were immerfed in it.* Blood, mixed with bile, became putrid in three days; while no mark of putrefaction .manifested itfelf in the bile till the fixth day.-f Hence alfo it is evi- dent, that putrid bile, which has been affigned as the caufe of bilious fevers, has no agency in its pro- duction ; for if the bile did, in reality, become pu- trid, this change muft neceffarily have previoufly taken place in the blood, in which ftate the animal muft expire within a few moments after putrefac- tion takes place. 4. On the application of thefe peftilential fluids, which have been confidered the caufes of the difeafes mentioned, to the bodies of men, which it may com- pletely furround in fome cafes, is it prefumed, are the various eruptions and petechia, fo common in fevers of the worft type, to be explained; and not often to be referred to critical depofitions of humors from the blood. Thefe affections will put on dif- ferent appearances and malignancy, in proportion to the concentrated ftate of the poifon, the consti- tution, and parts to which it is applied. From the difpofition of this acid to adhere to bed-clothes * On the Liver, p. 130. | On the Liver, p. no. ( 4° ) and bedding, of which there are innumerable in- stances, it will readily appear how thefe peftilential eruptions are produced, efpecially on thofe parts that are kept constantly covered, as the back, loins, &c. which are thus continually furrounded by an atmofphere of contagious vapours. The fkin, thus befet by this fluid, whofe particles feem to inhere in its pores, becomes inflamed, and puts on this morbid appearance. The yellow colour of the Skin, in fome cafes of'highly Contagious difeafes,1 feems to depend upon the fame caufe, and not to an abforption of bile, as has been fuppofed by wri- ters on bilious remitting fevers. If thefe changes of colour in the fkin were really owing to abforbed or to regurgitated bile, the colour of the urine, in thefe cafes, ought to be deeply tinged with this fluid*' and the feces to put on an afh-coloured appearance* as in jaundice; but none of thefe appearances are obferved to take place in the fevers where this pretended abforption is alledged. Befide, it is well known, that fuch parts of the fkin to which this poifon is artificially applied, will put on a yellow ap- pearance, refembling that which is obferved to take place in what is called yellow fever. It has been obferved, that perfons Sick with this fever, which had been taken in the Weft-Indies, had that part of their eyes which was, in vifion, expofed to' atmofpheric air, tinged with yellow; while the re- mainder of the eye retained its natural colour; In this cafe the eye could not have acquired this colour from an abforption of bile; which, if it bad been the cafe, would alfo have been evident in ( 4i ) ether parts of the eye and body. Were it not, pro* bably, for the perpetual fupply of tears, which wafh the eyes, and thus convey off any contagious fluids that may be applied, thefe appearances might of? tener occur, as impreffions would be quicker ob- ferved in this organ than on the fkin. £. This acid, in a vaporific form, does, no doubt, fometimes enter the trachea, with the air, in refpira- tion, where it may inflame and deftroy the parts with v/hich it comes in contaCf; and, in its paffageto the lungs, if in a concentrated form, may occafion fudden death. In this manner may the hidden ex- tinction of life, in perfons expofed to the contagion of the plague, as obferved by Ruffel, be accounted for,* If this gafeous fluid be infpired in fuch a dic- tated ftate as not to occafion immediate death, it may caufe catarrhal affections, anxiety, coma, fuf- focation, &c. depending on the fparfe or concen^ trated form, and circumftances under which it is applied. When mixed with atmofpheric air, and taken into the lungs, it will not ferve the purpofes of refpiration, as but a final! portion of vital air will be decompounded, owing to the large quantity of non-refpirable air which is taken in. The heat of the body muft thereby be lejjened, and the co:z- traCtions of the heart and arteries become more flovv and feeble. In this way may the purple and blackifh fpots of perfons dead of fever, occafion- sd by this acid and its oxyd, and the livid iind dark colour of the fkin, attended v.ith 9 Hiftory of Ah^po, p. a;v F ( 4^ ) coldnefs during life, be accounted for; the lungs not being able to reftore to the fyfterri its ufual and neceffary Supply of oxygene. Haemorrhages, debility, and proftration of Strength, together with want of cohesion in the folids, might all be explain- ed upon the fame principle, the mufcles being de- prived of their ufual quantity of oxygene, and over- charged with fepton. 6. If this acid be formed in the ftomach and in- teftines, or taken in by the faliva, and applied to the mouth, fauces, cuticular and pulmonic Surface, can it be fuppofed, that it Should not be taken up by the abforbent veffels of the fkin and pulmonic organs, or abforbed by the lacteals of the intef- tines, which are known, in fome inftances, even to take up fome of the fasces, and carried into the mafs of blood ? That fomething of a peftilential nature is conveyed into the blood, appears from the evi- dent marks of peftilential infection, which children, born of mothers fick with the plague, bring along with them. Whether they acquired this taint im- mediately from the blood circulating through the umbilical cord, or from the liquor amnii, or both conjoined, is immaterial to our prefent purpofe, as, in either manner, it goes to prove what has been faid above. The acid fweats thrown out from tHe poifoned mafs of blood, by means of the fmall exhalent arteries, in malignant and peftilential dif- eafes, forming the matter of contagion, and adher- ing to the bed-clothes and linen, which, by its cor- rofive qualities, it deftroys and rots; and, if excret- ed in any confiderable quantity, fo commonly' re- ( 43 ) Sieves the patient; inafmuch as the volume of poi- fon contained in the arterial fyftem is thereby lef- fened; fhews that the blood, in certain difeafes, con- tains fomething of a noxious nature. The appear- ances alfo which blood, drawn in peftilential fevers, puts on, correfpond with that in which feptic gas had been artifically injected.* Blood, thus infected with this poifon, taken up by the abforbent veffels, will be carried the round of circulation, and will continue to Stimulate the heart and arteries, wear- ing out their excitability, and, confequently, bring on death, if the constitution is incapable of becom- ing habituated to its ftimulus, or part, or whole, of the ftimulus be not fubduCted. If it be prefent in any great quantity, it may caufe a Sudden extinc- tion of the vital principle, as is obferved fometimes to happen in highly peftilential difeafes. 7. The above-mentioned compounds, when ab- forbed by the lymphatics, may inflame them, and caufe obstructions, indurations, and even Suppura- tion, of thofe glands through which they pafs, as is commonly obferved to take place in the inguinal and axillary glands, in the plague, and other dif- eafes produced by a peftilential ftate of the atmof- phere, where it is abforbed in a highly concentrated form. Inftances have occurred, where the lympha- tics of the hand, on this extremity being wounded, in diffeCting bodies, in which the feptic acid appears already to be formed, were highly inflamed, and * Vide Mitchill on the effe&s of contagion on the heart, in the-New- York Mag. for 1796. ( 44 ) £otiId be readily traced from the part where this fluid ^liad been applied, in their courfe to the glands' in the axilla, in which fubfequent Suppuration took £lace, fiefide the affections of thefe glands, thofe of the rtiefentery will be liable to like ailments; and more frequently, as this deleterious fluid will be more frequently applied to them, by reafon of its abforption from the intestines. The feptic com- pounds, pafling through the lacteals, will inflame them, and extend to the glands, in their way to the thoracic duct, and bring on an indurated or fchir- rous State : if it be abforbed in a highly concen- trated State, it may alfo communicate its effects to the ffiefentery. When thefe glands become in- durated or inflamed, the chyle will neceffarily be obstructed totally, or in part, in its circulation through thefe glands; confequently the fyftem will v not receive a Supply of noUrifhment equal to the quantity expended in performing its healthy func- tions. Hence the body muft' wafte away, and the difeafe named marafmus be induced. The frequent dropfical affections which follow long-continued in- termittents,"dyfenteries, and other difeafes of the fame clafs, appear, in many inftances, to be owing to obstructions of thefe glands* which do not allow a free paffage to the lymph, which is therefore de- posited in the different cavities and cellular texture of the body ** and in proportion as the obstruction is more or lefs univerfal, will the difeafe be gene- ral or local. ( 45 ) CHAPTER VI. Application of this Principle to explain the Preven- tion and Deflruclion of Infeclion, or Contagion, in Ships performing Quarantine, in Jails, Hofpitals9 private Dwellings, in regulating the Police of Ci- ties, in the Management of Lazarettos, &c. HAVING fhewn the operation of the feptic acid, on its application to the conftitution, we come next to confider its prevention and destruction in (hips, performing quarantine, &c. &c. i. In fuch Ships as have thefe noxious effluvia floating about, either derived from articles infected, or generated from the collection and putrefaction of fuch materials as contain fepton, it will be pro- per, from the known affinity which fubfifts between thefe contagious vapours and Calcareous earth (lime), to expofe this fubftance to an atmofphere thus impregnated. White-wafhing between decks, and all fuch places as may admit of this practice, will therefore be the moft advantageous method in which it can be applied, as a larger Surface will thereby be expofed, and, confequently, a greater portion of the acid taken up and neutralized in a given time. Frequent repetitions of this practice will be neceffary where the contagion is abundant, as the lime will become faturated with this princi- ple, and incapable to attract and take out of circu- lation any more of the noxious compound. In fuch inftances where thefe effluvia have, for any ( 46 ) length of time, been prefent in veffels, it is more than probable, that from the capability existing be- tween the two to unite, the timber of the latter may imbibe fome of thefe vapours j and to this, as has been above remarked, may it be owing, that the fucceflive crews of certain veffels are fornetimes deftroyed. To deftroy this connection between thefe two bodies, as well as to prevent the future afcent of the gas, and thus again taint the circum- ambient atmofphere, a folution of the vegetable alkali (pot-afh), in water, which pofTeffes the greateft known affinity for this fluid, will be a proper pre- ventative. It will difengage the acid from its con- nection with the wood, in confequence of this Su- perior attraction, and join with it itfelf. Frequent wafhing the apartments will likewife tend greatly to cleanfe and carry off the noxious vapours; and will alfo, by being imbibed into the texture of the wood, fet loofe and convey away fuch poifon as may remain. Ventilation muft not be neglected ; the, contaminated atmofphere will thereby have part of its volume conveyed off, and a quantity of purer air admitted; thus rendering its Stimulating quality lefs violent and active. 2. The fame means, recommended above, for the destruction of thefe fluids in fliips, will apply to jails.—As white-wafhing the walls with lime can at all times and readily be done here, it ought, from time to time, to be renewed; the poifonous effluvia being thus constantly taken up, and rendered harm- lefs. Wafhing the apartments with water or ley, which has a Still greater affinity for thefe effluvia, will ( 47 ) difengage the poifon which they fo commonly be- come impregnated with, to the injury oS the health of the inhabitants of thefe places. In no one inftance will it be more neceffary to admit frefh air, than in thefe places. The pent up vapours will, in a Short time, acquire a high degree of malignancy, and caufe difficulty of refpiration, uneafinefs about the precordia, and bring on other fymptoms indicative of a vitiated ftate of the atmofphere. 3. The regulation of hofpitals will be anfwered by the fame means already noticed for jails and fhips : but, from the Specific gravity of this acid or its oxyd, it will occupy the lowermoft parts of the rooms. " Under an atmofpheric preffure which fupports the quick-filver in the barometer at 29. 84 inches, and in a temperature of 54. 5 of Fahren- heit, a cubic foot of azotic gas weighed one ounce, thirty grains and one half; and of oxygenous gas, one ounce, one drachm, and fifty-one grains: it is prefumable that a combination of the two, that is, thirty-feven parts of oxygene united to thirty- three of azot^ would form a fluid of nearly the fame weight with atmofpheric air, or rather heavier; and the probability of this would increafe, by con- sidering that a cubic foot of nitrous gas, which con- tains only thirty-one parts more of oxygene than the gafeous oxyd does, weighs one ounce, two drachms, and thirty-nine grains." Hence, then, perfons who lay on or near the floor, where this compound is prefent, will Suffer more than thofe who walk through thefe places; and for this reafon alfo will the atmofphere on the fecond floor be ( 48 ) more refpirable than that on the firft, dr lowefi. Vent-holes, upon a level with the lowermoft part of the room, may therefore more readily fuffer the efcape of thefe noxious compounds; and, in ad* dition with thofe fubftances that take up and neu- tralize them quickly, reftore the purity and refpi- rability of the air. 4. The prevenfatives already mentioned, parti- cularly for Ships, which may be confidered as float- ing habitations of men, will alfo apply to the cleanf- ing and purification of private dwellings. From what has been faid on the affinity of lime with the feptic acid, it will, at firft view, appear how much more preferable, and conducive to the health of .the inhabitants, fuch dwellings, which have their walls plaiftered with this fubftance, will be, to thofe ,of gypfum (Sulphate of lime), which is incapable to neutralize the acid. The common practice to pre- vent and deftroy contagion in private dwellings, by means of alkalies diffolved in water, fuch as ley, he. and lime, fhews how much preferable this ma- nagement and contrivance is to that of burning tar, coal, fulphur, &c, fubftances that poffefs no ufe- ful, but pernicious qualities, inafmuch as the pek tilential matter refiSts the attractive powers of thefe fubftances. (Vide feet, vii). 5, In regulating the police of cities, it will, at firft view, appear highly neceffaryv in order to pre- vent the formation of thefe noxious fluids, to re- move all the materials, fuch as animal and certain vegetable fubftances, from which they are generated. In addition to the preventatives enumerated for the ( 49 ) prevention and destruction of contagion in jails, &c. planting trees along the Streets, especially thofe which are, from fituation, more liable to collections of gafes of this kind, will be of fervice in decom- pounding thefe fluids, as foon as formed, if in con- fiderable quantities, and thus reftore the air to its former ftate of refpirability. " Thefe very fub- ftances (putrefying bodies and Street-manure), that caufe fo much mifchief and terror in cities, are fought after with great avidity by farmers, who pur- chafe them at a high price, and ufe them, with much advantage, to fertilize their fields. The beneficial and falutary effects of this practice in husbandry, makes it look as if nitrous acid and nitrous airs were good manures, and that vegetables had the power of decompounding them. That, in fhort, in the economy of plants, there is a procefs by which the fepton and oxygene of thefe infectious fluids are feparated; and while the former remains in the ve- getable as a part of its nutriment, the furplufage of the latter, after forming gum, mucus, meal, &c. and other vegetable oxyds, flies off through the up-; per Surface of the leaves, in company with heat and light, in the form of vital air." (Vide Mitchill on the decompofition of contagious air by vegetation. New-York Mag. for 1797.) The luxuriant growth of vegetables in the Sum- mer and autumn of 1795, in New-York, during the epidemic, makes it further evident, that vege- tables decompound this noxious body, and thus aCt in a beneficial and falutary manner. Upon this principle in vegetables to deftroy the chemical G ( S° ) union between the ingredients of feptous airs, may the dangerous confequences often attending the cutting down of woods in new and uncultivated countries, be accounted for. The exhalations from the fwamps, moraffes, &c. being fet loofe in greater quantity in the atmofphere, by the now more di- reCt rays of the fun, without any adequate fupply of other vegetable fubftance to arreft and decom- pound them, they afcend, and pervade the air, car- rying on their ufual noxious and deleterious qua- lities, on meeting the bodies of men, or brute creation. 6. The management of lazarettos may be conduct- ed upon the fame principle. From the known mifci- bility of contagion with water, and the fhortdiftance thefe fluids extend their influence over this body, as has been repeatedly obferved by Lind, and others, the moft proper and healthy Situations for institu- tions of this kind, are readily pointed out. And, 7. According to what has been faid in the fifth chapter, concerning the production of contagious fluids in the ftomach and inteftinal tube, from ani- mal and certain vegetable food, taken in from time to time, it will appear, that fuch fubftances as con- tain fepton to any amount, fuch as lean and muf- cular animal fubftances, are improper ingredients in diet. Such articles, then, as contain none of this principle, ought to be feleCted as the moft pro- per for nourishment in complaints occafioned by this acid. Fat or oily fubftances being of this clafs, and vegetables containing but little fepton, ought to be the moft beneficial and wholefome diet in ma- ( 5i ) lignant and peftilential difeafes. This is authen- ticated by facts Sufficiently numerous to put it be- yond cavil. The comparative health, in the Weft-Indies, be- tween the Englifh, who indulge in the free ufe of animal food, and the French, who, on the contrary, abftain from this kind of aliment, and live princi- pally on vegetable food, Shews that animal matter is not only improper, but is an injurious article in our diet, in all peStilential conditions of the atmof- phere, or when malignant difeafes prevail. The fame is obferved to happen in Bengal, and other parts of the Eaft-Indies. The Englifh, who live principally on animal and vegetable food, are far more liable to attacks of malignant difeafes, and a greater number of them are carried off annually thereby, than of the Gentoos and Brahmans, who live on rice. Befide, it is well known how much lefs fatal the yellow fever, and other Species of malignant difeafes, are among the negroes of the Weft-Indies, and thofe of the fouthern States, who live on vegetable food for the moft part, than,among the whites of thefe places, who are under no necef- $ty of abstaining from the ufe of animal food. M^ v : -v : ( S3 ) APPENDIX. EXPERIMENT I. JL TOOK two mice; one I caufed to be Stung by a wafp, which was immediately thrown into con- vulfions, and expired in two minutes; into an incifion made in the mufcular fubftance of the other, I injected two drops of the nitrous acid; it feemed to operate exactly in the fame manner as the Sting of the wafp* and the animal expired im- mediately. On opening them, and endeavouring to Stimulate the mufcular fubftance of their hearts, I found it had in a great meafure loft its irritability. Fontana obferves, in his book upon Poifons, that the nitrous acid, applied to the mufcular fubftance of a pigeon, killed it immediately; CaVendiSh and Lavoifier have proved, by experiments, that the azote is the radical principle of the nitrous acid. EXPERIMENT III. I took four young puppies; into the jugular vein of one, I injected four drops of the decoction of white helebore; into the fecond, I injected four ( 54 ) drops of the digitalis; into the third, I injected one grain of the fait of urine diffolved in water'; the fourth I caufed to be Stung by two wafps; • the firft died almoft inftantaneoufly; the fecond and third m lefs than five minutes; the fourth recovered with great difficulty, and feemed to throw off the dif- eafe by foaming at the mouth. EXPERIMENT IV, I caufed a number of earth worms to be Stung by bees, ants, and other infects, which always killed them immediately; and feemed to act on them in the fame manner as the decoction of the poi- fonous plants, the laurel, tobacco, opium, &c. This effect is aftonifhing, in thefe animals, which, when cut into pieces with the knife, Still retain their irritability for many hours, or even days. All poifonous plants with which we are acquaint- ed feem to act in the fame manner when injected into the circulating fyftem of animals; yet, from the nature and construction of the Stomach of fome animals, they are eaten with impunity : goats will . grow fat upon euphorbium, and Swine upon hen^ bane, &c. THE END. LS"74l C-ZL