PUTREFACTION. 



power, but that they exceed the acids in their efficacy for 

 corrcdting putrefaflion ; that fermenting and effcrvcfcent 

 mixtures are the molt powerful of all known antifeptics ; 

 and, in general, that whatfoever hath a power to reilrain 

 the efcape of the fixed air, or hinder the inteftine motion, 

 mud of courfe prevent putrefaftion ; and that fixed air, 

 when transferred frjm a found body to one that is putrid, 

 appears to reftore to that body the principle which has been 

 dellroyed or loll. 



Dr. Macbride objefts againlt the adminillration of acids 

 in putrid difeafes, for the following reafons ; becaufe, if 

 they came unchanged to the abforbent velTels, they would 

 not admit of them, and if they did, they would be dan- 

 gerous, and they are quite changed before they leave the 

 prims vije. Dr. Crell (Phil. Tranf. vol. Ixi. part i. p. 340.) 

 has replied to this reafoniiig, and propofed experiments to 

 prove, that acids, though changed in the alimentary canal 

 lo far as not to effervefce with alkalis, may, notwitiiltand- 

 ing, check putrefaftion, and, therefore, that their ufe is of 

 great confequence, and ought not to be omitted in putrid 

 difeafes. 



With regard to the exhibition of ilkalis, Dr. Macbride 

 obferves, that the point is not yet fatisfaftorily fettled. 

 There can be no doubt of their power to refill and correA 

 putrefaftion in dead bodies ; but whether, upon the pre- 

 iumption of this virtue, they can be given with propriety 

 as antifeptics, he adds, is not fo clear. Dr. Crell affirms, that 

 they can never be ufed in living bodies as antifeptics ; for, lay- 

 ing alide their ftimulating quality, which mull prevent their 

 ufe in mod of the putrid difeafes, they would, he apprehends, 

 increafe the morbific matter, by being intimately mixed by cir- 

 culation with phlogillic matter, which they find abundantly 

 in fuch bodies. Aftringents, fays Dr. Macbride, prevent 

 putrefaction very powerfully, but they have not the leall de- 

 gree of efficacy in correfting it ; and as antifeptics, they 

 can be of importance only in thofe cafes where, from ex- 

 treme relaxation and refolution of the folids, the difTolved 

 fluids are fullered to tranfude, and either form fpots of dif- 

 ferent hues, or run off by aftual haemorhage ; and he appre- 

 hends, that acids act in thofe cafes where they have been ad- 

 minillered with fuccefs, merely as aitringents. The antifep- 

 tic virtue of the gummy-refinous vegetables, judging of their 

 effedl by that of the bark, appears to depend on their fer- 

 menting in the body, and parting with fixed air in the courfe 

 of their fermentation, and throwing a great quantity of it 

 into the blood ; and attending to the things that prevent 

 putrefaftion in living bodies, we fhall find that the dependence 

 is on the quantity of air. Thus, vegetable food prevents 

 the putrefaftive diathefis ; and to the frequent ufe of frefh 

 vegetables and fugar, in the diet of the European nations, it 

 is owing that putrid difeafes or plagues are now fo uncom- 

 mon. And what proves almoll to ademonftration the anti- 

 feptic power of the fermentable fubftances, is the cure of 

 the fea-fcurvy. 



Dr. Crell difagrees with the opinion of Dr. Macbride, 

 that putrid difeafes may be cured with fermentable fubftances 

 only ; nor is he convinced that putrefaftion depends only on 

 the lofs of fixed air. This, he apprehends, is an effeft ra- 

 ther than the caufe of putrefaftion. We lliall here only add, 

 that Dr. Macbride recommends,' in the putrid yellow fever 

 of the Weft Indies, to give the patient repeated dofes of 

 the alkaline falts, in frefli hme-juice, or the like, and to let 

 it be fwallowed during the efFervefcence ; and to order the 

 patient's drink to be fomewhat of the highly fermentable 

 kind ; fuch as the juice of the green fugar-cane, diluted and 

 acidulated with fome of the recent four juices. The natives 

 on the coaft of Africa give in fevers of this kind, with good 

 Vol. XXIX. 



fuccefs, a drink prepared by macerating in water a fruit of 

 the plum kind, that grows there in great plenty. He adds, 

 that by throwing in fuch a quantity of antifeptic vapour as 

 would be furnifhed from this kind of materijJs, the putre- 

 fadlive acrimony, which at firll (eems chiefly to afFedl the 

 biliary fyftem, might be corredled and faturated. See on 

 the fubjeft of this article Dr. Macbride's Eliays, 1776, 

 paffim. 



Putrefaction, in PhyRology, the fpontaneous changes 

 which animal fubftances undergo, wh^n deprived of life. 

 See Death. 



Putrefaction, in ylgrkuUnre. It is by means of putre- 

 faftion, as ftated under its appropriate article, that various 

 fubftances and bodies are decompofed, reduced, and brought 

 into the ftate proper for being applied to lands for tiie 

 fupport of crops ; but this is more fully explained, in fpcak- 

 ing of the nature of the different materials that are capa- 

 ble of being made ufe of in ameliorating land for the grovnh 

 of crops. See Manure. 



Putrefaction of Water. It is faid to be the peculiar 

 quality of the Thames water, that it will ftink and yet be 

 wholefome ; and after this will recover itfelf again. Many 

 failors have been obliged to drink it ftinking, fo that they 

 held their nofes while they poured it down their throats, yet 

 no ficknefs enfued from it. It generates a fort of fpirit alfo 

 in this ftinking ftate, which will take fire at the approach of 

 a lighted candle, as if fpirit of wiae were touched by the 

 fame. 



It appears from the article Putrefaction, that though 

 a volatile alkali may be obtained from putrid fubftances by 

 diftiUation, fuch fubftances mull not be fuffered to remain too 

 long before they are diftilled, unlefs they are kept in clofe 

 veflels ; becaufe the volatile alkali, which is the offspring of 

 putrefaftion, is diffipatcd as faft as it is generated, infomuch 

 that, at length, nothing is left behind but an infipid water, 

 or a fohd matter, being an earth fimilar to common mould. 

 It is in this way, fays Dr. Macbride, that ftinking water, 

 after fome time, becomes fweet : the volatile alkali, gene- 

 rated by the putrefaftion of the animal and vegetable fub- 

 ftances at firft contained in the water, being, after a while, 

 entirely diffipated, leaves the remainder without any difagree- 

 able fmell. 



Putrid water is immediately deprived of its offenfive fmell 

 by charcoal. If putrid water be agitated with a fmall quan- 

 tity of magnefia, it will lofe its bad tafte and fmell in a few 

 minutes. See Crell's Journal, and Prouft, Journal de Phy. 

 fique. 



A method of preferving water free from putrefaftion was 

 fome years fince propofed by Dr. Alfton. It confifted in 

 adding a quantity of lime to every caflc of water ; and as lime 

 is known to have a ftrong antifeptic property, water, as 

 long as it retains the impregnation of lime, never putrefies. 

 In order to free the water, at the time of ufing it, from 

 the lime, Dr. Alfton propofes the precipitation of the lat- 

 ter by throwing a quantity of magnefia alba, on this princi- 

 ple, that as lime-ttone is rendered foluble in water by the 

 deprivation of its fixed air, and has a greater affinity with 

 that air than magnefia has, the particles of quicklime diflblved 

 in the water would attraft the air from the magnefia, and 

 thereby becoming ho longer foluble, would fall to the bot- 

 tom, and leave the water taftelefs and fit for economical ufes. 

 See LiME-wa/cr and Magnesia. 



The expence, however, attending this procefs prevented the 

 execution of the propofal. Mr. Henry has not long ago fug- 

 gefted a cheap and eafilyprafticable method of precipitating 

 the hme, and thus of reftoring the water to its original tafte. 

 The following is aftiort flcetch of the author's procefs. To 



H preferve 



