S66 COOLING OF ANIMALS EXPOSED TO GREAT HEAT. 



same time, ami side by side, in a stove, various animals^ 

 alcarrazas filled with water, and wet sponges. In making 

 this experiment, which I have several times repeated, I 

 constantly observed, that the alcarrazas and sponges, 

 w hether I introduced them into the stove cold, or previous- 

 ly warmed, assumed a temperature below that acquired by 

 the warm-blooded animals, but nearly the same as that of 

 the cold-blooded*. From these results then we may infer, 



Evaporation an that evaporation is sufficient, to produce a refrigeration as 

 adequate cause. , . „ , , , , . 



great, it not greater than that observed ih animals; and 



hence v/e may presume, that it is the cause of the latter. 

 It would be wrong however, to consider the latter as a ne- 

 cessary consequence of the preceding proposition. The 

 possibility of a thing is not a sufficient ground for our con- 

 cluding, that it actually is. Accordingly, when I publish- 



* To render the experiment completely accurate, it would have 

 been necessary to ascertain the final temperature, that would have 

 been acquired both by the animals and the inanimate substances, 

 when the heat had produced its utmost effect on them. This I 

 found very difficult with respect to warm-blooded animals : a long 

 continued heat exhausting them greatly, I satisfied myself with an 

 approximation to the limit. I generally waited, tilj the inanimate 

 substances had attained it; which was much more easy, because I 

 took care previous to the experiment, to raise their temperature 

 nearly to the point, at which it would ultimately arrive by their 

 exposure in the stove. 



I shall here give the result of two experiments of the same kind, 

 lately tried. 

 Results of ex- I enclosed in one basket, separating them only by an open par- 

 periments. tition, a rabbit, and an alcarraza full of water; and placed them 

 in a stove, the mean heat of which, during the experiment, was 

 43" [113° F.]. The temperature of the rabbit, when introduced, 

 was 39-7 <» [103 ■46" F.] ; that of the alcarraza about SS** [95* F.]. 

 The temperature of the rabbit gradually rose to 43-8" [11 0-84 "F.] ; 

 that of the alcarraza, on the contrary, fell t© 31-4*' [88-52'' F.], at 

 which point it appeared to continue stationary. 



In the second experiment I exposed, in the same stove, to a 

 mean temperature of SO'S** [97-7? F.], two small sponges and a 

 frog. The latter, which was placed between the two sponges, ac- 

 quired, in the course of an hour, the stationary temperature of 

 28 2' •[82-76<' F.], the sponge on the left that of 27-9* [82-22" F.], 

 and the sponge on tfee right that of 27 6' [81 -68" F.]. 



