$10 ANIMALS AND VEGETABLES IID 
fhall afterwards fpeak, I cannot admit that ani« 
mals die from obftructed refpiration. Several vi- 
pers and frogs were confined in very {mall veffels 
where many animals were already dead, and an 
equal number put at the fame time in vacuo. It 
is incredible how much fooner the former died ; 
fome did not furvive a minute; but thofe in vacuo 
were alive at the end of feveral hours. It was not 
fuffocation, therefore, or any obftacle to the air 
entering into the lungs, that occafioned death, 
otherwife the animals would have lived much 
longer, at leaft as long as thofe in vacuo. 
Frogs were alfo forced to remain under 
water, and prevented from rifing to refpire at . 
the furface. I have tied the origin of the 
lungs in fuch a manner that the air could not en- 
ter. Some I have deprived of the lungs, and 
confined along with other frogs in a {mall quan- 
tity of air very foetid from the exhalations of 
refpiration. The laft expired in a few minutes, 
fometimes in one, even in lefs ; while thofe pre- 
yented from refpiring by immerfion in water, 
having the lungs tied or cut out, have lived, as 
thofe in vacuo, for feveral hours. I have found 
the fame with toads and water ferpents. Since , 
the death of all thefe fpecies, by privation of ref- 
piration, has been without comparifon later than 
the death of the fame animals killed by the ex- 
halations of refpiration, we muft conclude that 
thele 
