[ T 9° ] 
•in it; ' " ime, amt 
is equally noxious to annuals ; but they affect the air. 
very differently if the heat tii. t is er; i led to them be 
' con fide rabie. If beef or mutton, raw, or boiled, be 
placed fo near to the fire, tint the iw.it to which it 
•is expofed fhall equal, or rather exceed, that of the 
blood, a confiderable quantity of air- will be generated 
•in a day or two, vliout gth of which I have generally 
found to be abi'orbed by water, while all the reft was 
inflammable ; but air generated from vegetables, in 
the lame circumflances, will be almoft all fixed, and 
no part of it inflammable. This I have repeated 
again and again, the whole procefs being in quick- 
Jilver ; fo that neither common air, nor water, had 
•any accefsto the fubffaqce on which the experiment 
•was made -, and the generation of air, or effluvium 
.of any kind, except what might be abforbed by 
quicklilver, or reforbed by the fubftance itfelf, might 
• be diftinftly noted. 
-A vegetable fubftance, after {landing a day or two 
in thefe circumflances, 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 fome 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 quicldilver, 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 
iimell fufficiently indicates - } and this effluvium does 
either 
j. 
