Cold in Animal Bodies. 
5 
fort poflefs it; for if touched, they feel cold. 
This proves only, that their heat is lefs than that 
of the hand, with which they are felt; and per¬ 
haps lefs than that of the air, when the trial is 
made. 
But it is extremely probable, that no animal 
whatever can live in health, for any confiderable 
time, in an atmofphere of a temperature fuperior 
in heat to that of its own blood. Thus we find, 
that the animals in queftion hide themfelves in 
the day-time among thick grafs, where there is 
a great evaporation; and in places, into which 
the rays of the fun cannot penetrate. Worms, in 
hot weather, during the day, lie deep in the 
ground; but in the night-time, when it is cool, 
rife to the furface to refrefli themfelves in the dew. 
When frogs, worms, and fuch other animals are 
expofed to air warmer than their blood, its influ¬ 
ence is counteracted by the fame caufes which 
counteract its influence on the human body, the 
evaporation from the furface of their bodies, and 
the coldnefs of their blood. Such accidental 
expofure happens more frequently to them, than 
to the human fpecies ; and, from the inferiority 
of their fize, they would be fooner heated through, 
and lefs able to refift the noxious effeCis of the 
hot air, were not their power of refilling it made 
up in another refpedt. In fuch fituations, the 
evaporation from the furface of their bodies is 
greater; for their fkin is more lax, and is always 
B 3 covered 
