152° ANIMALS KILLED) Wa 
revived wheel animals fhould not fupport the: 
fame degree as thofe which are dead ; if, on the’ 
other hand, thefe laft facts did not evince that< 
when the cold begins to act powerfully on thofe 
revived, they pafs from life to death, as’ appears’ 
by the ceffation of motion, their contraGtion and’ 
disfiguration, fo that they become exactly as: 
when evaporation of the water leaves them» 
dry.in the fand. But I do not. know that the 
aétion of extreme cold will deprive living wheel. 
animals of lifes. It is certain that it could not’ 
deftroy animaleula equally delicate, fuch as fome 
infufion animalcula and the eels of vinegar. Yet, 
what is more furprifing, the animalcula of infu- 
fions and the eels of vinegar perifh with lefs heat 
than wheel animals: they cannot fupport more 
than 111°.-At that degree feveral fpecies of beetles, . 
chryfalids and caterpillars, perifh, as I before ob- 
ferved, though they can fupport 34° below freez- 
ing. This fhews that many animals in fimilar 
fituations can fupport cold better than heat.. 
From the facts hitherto related, we colle& that 
there are two principal caufes deftrutive of the 
vefurgent: quality in wheel. animals, the want of. 
fand and of heat. Are there others alfo produc- 
ing the fame effe&? 1 could difcover it only by 
conjecture, and ufing the different methods pre- 
judicial to the produétion and life of other ani- 
mals, efpecially of thefe bearing the greateft ana-- 
logy 
