162 ANIMALS AND VEGETABLES TIE 
CHAP. II. 
WHETHER THE RESPIRATION OF ANIMALS IN STAG- 
NANT AIR OCCASIONS THEIR DEATH.—WHY THE 
DEVELOPEMENT OF SEEDS AND EGGS IS, IN CER~ 
TAIN SITUATIONS, PREVENTED BY CONFINED AIR. 
"Tugez points are to be examined in difcuffing 
the firft queftion; Whether the death of animals 
in confined air is occafioned by their refpira- 
tion? r. If we actually find exhalations in clofe 
veflels where animals have died: 2. If the ex- 
halations occafion their death: 3. Suppofing they 
are noxious, how do they operate ? 
With regard to the firft article, Sig. Cigna, 
the learned illuftrator of this theory, has proved 
the reality of the exhalations of refpiration, by. 
the foetid odour we are fenfible of on opgning. 
the veffels where animals have died, and a fort of 
vaporous pellicle covering the internal furface. In 
my experiments, I have almoft uniformly obferved 
this pellicle over the internal furface of the vel- 
fels where warm blooded animals, as_birds,. 
rats, or bats, have died, but never have re- 
marked it. with cold blooded animals. Some- 
thing, . 
