[Il. cONFINED IN STAGNANT AiR. 107 
_ Although I conceive it impoffible that any ani- 
mal can live in confined air, if the veflels are 
very fmall, it is certain that fome furvive much 
longer than others. Cold blooded animals ge- 
nerally exift longer than warm. In the fame air 
where a newt or a frog will live a day, a {par- 
row, a bat, or a-rat, frequently do not live an 
hour. There is even a fort of gradation among 
cold blooded animals. A newt lives longer than 
a frog, and a frog fhorter thana leech. This 
alfo fucceeds with infects. In the opinion of 
fome, it is not difficult to afcribe a reafon for the 
diverfity of thefe phenomena. Cold blooded 
animals are ngt only more tenacious of life, but 
they have incomparably lefs neceflity to refpire 
than the warm blooded have. How much long- 
er will a frog, a viper, or a toad, furvive in vacuo 
than a bird? Not being under the fame necefflity 
to refpire as the others, they will abforb lefs of 
the exhalations in equal time. Why then is it 
wonderful if they live longer? Doubtlefs fome. 
analogous reafon occafions the difference of time 
that cold and warm blooded animals can live in 
clofe veffels. Experiment proves that frogs in 
vacuo die fooner than newts; and I have found 
the fame on keeping both immerfed in water. 
We may reafon in a fimilar manner on infeés, 
not to {peak of their different conftitution, which 
may produce difcrepancies. 
ita 
