PUTREFACTION. 



are equally noxious to animals, are equally and in tlie fame 

 way offenfivc to the fmell, equally precipitate lime in lime 

 water, and are rcflored by the fame means, Dr. Prieftley 

 fuggefts, that one ufe of the lungs is to carry ofl' the 

 putrid effluvia, without which, perhaps, a living body might 

 putrefy as foon as a dead one. See Blood and Rksimra- 



TION. 



We fliall here obfervc, that putrfying and fermenting 

 fubftances have been found, by the experiments of Mr. 

 Cavendiili, Dr. Prieftley, &c. to yield not only fixed but 

 vijlammahk nir. From an experiment of Dr. PriaiHey, in- 

 tended to determine the proportion of each of the kinds of 

 air in the different ftagcs of the putrefaftive procefs, it 

 appears that a piece of mutton weighing four penny-weights 

 fix grains, yielded in all 244 mcafures o{ air, ot which 2^,', J- 

 was fixed, and the reft inflammable ; and that all the in- 

 flammable part wasexhaulled a confiderable time before the 

 fixed air. The fame ingenious writer has obierved, that tlie 

 diminution of common air, by means of putrefaction, amount; 

 to a complete fourth part of the whole, notwithltanding tlie 

 produftion of fome permanent air from the putrefying fnb- 

 ftance, and has, in all rcfpeifls, the appearance of being 

 produced folely by the precipitation of fixed air. It mull 

 occur to every reader, in any way acquainted with tliis fub- 

 jeft, if the phlogiftic theory be admitted, (which indeed 

 is now generally difcarded, ) that if inflammable air be tlie 

 fame with phlogifton, as Dr. Prieltley feemed to have 

 difcovcred, many of the phenomena of putrefaftion, de- 

 pending on this principle, fuch as the fmell, colour, light, 

 &c. will probably from hence admit of an eafy explication. 



We fhall here fubjoin fome obfervations with refpeft to 

 the decompofition of animal bodies that are interred in 

 burying-grounds. In this fituation, the decompofition is 

 four times as flow as when the putrefying animal is expofed 

 to the air. It is not perfeAly ended, according to Mr. 

 Petit, till three years after the body has been interred, at 

 the depth of four feet ; and it is flower in proportion as the 

 body is buried at a greater depth. Thefe fa£ls agree with 

 the principles which we have already eilablilhed for bodies 

 buried in the earth, and fubjedled to laws of decompofition 

 very different from thofe vi-hich take place in bodies expofed 

 to the open air. In this cafe, the decompofition is favoured 

 by the waters which filter through the earth, and diflolve 

 and carry with them the animal juices. It is alfo favoured 

 by the earth, which abforbs the juices with more or lefs 

 facility. MefTrs. Lemery, Geoffroy, and Hunaud, have 

 proved that argillaceous earths exert a very flow aftion 

 upon bodies ; but when the earths are porous and light, the 

 bodies then dry very fpeedily. The feveral principles of 

 bodies abforbed by the earth, or carried by the vapours, 

 are difperfcd tbrough a great fpace, imbibed by the roots 

 of vegetables, and gradually decompofed. This is what 

 pafTes in buryin-g-grounds in the open air ; but it is very far 

 from being applicable to the fepulchres which are made in 

 churches and covered places. Here is neither water nor 

 vegetation ; and confequently no caufe which can carry 

 away, diflolve, or change the nature of the animal fluids : 

 and we cannot but applaud the wifdom of government, which 

 has prohibited the burying in churches ; a praftice which 

 was once a fubjeft of horror and infeftion. 



The accidents which have happened at the opening of 

 graves and vaults are but too numerous, to render any 

 apology neceflary for our fpeaking a few words refpefting 

 the method of preventing them. 



The detompofition of a body in the bowels of the earth 

 <ran never be dangerous, provided it be buried at a fufficient 

 (depth, and that the grave be not opened before its entire and 



complete decompofition. The depth of the grave ought ty 

 be fuch that the external air cannot penetrate it ; that the 

 juices, with which the earth is impregnated, may be con- 

 veyed to its furface ; and that the exhalations, vapours, or 

 gafes, whicli are developed or formed by decompofition, 

 fliould not be capable of forcing the earthy covering which 

 detains them. The nature of the earth in which tlie grave 

 is dug, influences all its effefts. If the flratum which covers 

 the body be argillaceous, the depth of the grave may be 

 lefs, as this earth difficultly affords a paflage to gas and 

 vapour ; but in general it is admitted to be neceffary that 

 bodies fhould be buried at the depth of five feet, to prevent 

 all thefe unhappy accidents. It is likewife neceffary to at- 

 tend to the circumftance, that a grave ought not to be 

 opened before the complete decompofition of the body. 

 This decompofition, according to Mr. Petit, is not perfedl 

 until the expiration of three years, in graves of four feel 

 depth ; or four years, when they are fix feet deep. This 

 term affords many varieties, according to the nature of the 

 earth, and the conftitution of the fubjefts buried in it ; but 

 we may confider it as a medium. The pernicious cuftom, 

 which allows a fingle grave to families more or lefs nu- 

 merous, ought therefore to be fuppreffed ; for in this cafe, 

 the fame grave may be opened before the time prefcribed. 

 Thefe are abufes which ought to occupy the attention of 

 government ; and it is time that the vanity of individuals 

 fnould be facrificed to the public fafety. It is likewife ne- 

 ceffary to prohibit burying in vaults, and even in coffins. 

 In the firfl cafe, the principles of the bodies are fpread into 

 the air, and infeft it ; in the fecond, their decompofition is 

 flower and lefs perfeft. 



If thefe precautions be negicdled ; if the dead bodies be 

 heaped together in too confined a fpace ; if the earth be not 

 proper to abforb the juices, and decompofe them ; if the 

 grave be opened before the entire decompofition of the 

 body ; — unhappy accidents will no doubt be produced ; 

 and thefe accidents are but too common in great towns, 

 where every wife precaution is neglefted. An inftancc of 

 this happened, when the ground of the church of St. Benoit 

 at Paris was dug up a few years ago : a naufeous vapour 

 was emitted, and feveral of the neighbours were aflefted by 

 it. The earth whicli ivas taken out of this grave was 

 unftuous, vifcid, and emitted an infeftious fmell. MefTrs. 

 Maret and Navier have left us feveral firailar obfervations. 

 Chaptal's Elem. of Chem. vol. iii. 



Putrefaftion is one of the inftruments in nature by which 

 many great changes are brought about. In the procefs of 

 vegetable putrefaftion, if we throw together any of the 

 tender, green, and fucculent parts of recent vegetables, 

 whether acid or alkaUne, in a large heap, in the warm open 

 air, and prefs them down with an additional weight, if their 

 own be inconfiderable ; the middle part of the heap will, in 

 a little time, fpontaneoufly conceive a fmall degree of heat, 

 and pafs fucceflively through the other degrees, till it arrive 

 at a ftate of ebullition, and be perfectly putrefied. 



In the fpace of three days, from the firfl putting them 

 together, they will yield a heat, perceivable by the hand, 

 c(]ual to that of a human body in a healthy ftate ; by the 

 fifth, the heat will be too great for the hand to bear with- 

 out piin ; and, laflly, by the fixth, feventh, or eighth day, 

 the juices will generally appear ready to boil ; and fome- 

 times the matter will even flame, and burn away. 



By this fpontaneous operation, the vegetable acquires an 

 abominably putrid, ftercoraceous, or cadaverous, tafte and 

 odour ; and turns entirely into one foft, fimilar, pulpy mafs, 

 or crafTamentum, greatly refembling foetid human excre- 

 ments in the fcent, and putrefied flefli in the tafte. 



If 



