In its dimenfion?, it equally extinguifhes Oaine, and 

 is equally noxious to animal's ; but they affect the ail* 

 very differently if the heat that is applied to them be 

 coniiderable. If beef or mutton, raw, or boiled, be 

 placed fo near to the fire, that the heat to which it 

 is expofed fliall equal, or rather exceed, that of the 

 blood, a coniiderable quantity of air will be generated 

 in a day or two, about -^-th of which I have generally 

 .found to be abforbed by water, while all the reft was 

 inflammable ; but air generated from vegetables, in 

 the fame circumftances, will be almoft all fixed, and 

 no part of it inflammable. This I have repeated 

 again and again, the whole procefs being in quick- 

 silver j fo that neither common air, nor water, had 

 any accefs to the fubftance on which the experiment: 

 was made ; and the generation of air, or effluvium 

 of any kind, except what might be abforbed by* 

 quickiilver, or reforbed by the fubftance itfelf, might 

 be diftindtly noted. 



A vegetable fubftance, after {landing a day or two 

 in thefe circumftances, will yield nearly all the air 

 that can be extracted from it, in that degree of heat ;- 

 whereas an animal fubftance will continue to give 

 more air or effluvium, of Tome kind or other, with 

 very little alteration, for many weeks. It is re- 

 markable, however, that though a piece of beef or 

 mutton, plunged in quickiilver, and kept in this de- 

 gree of heat, yield air, the bulk of which is inflam- 

 mable, and contracts no putrid fmell (at leaft, in a 

 day or two), a moufe treated in the fame manner, 

 yields the proper putrid effluvium, as, indeed the 

 imeii iufiiciently indicates 3 and this effluvium does 



-either 



