Animals poffefs of producing Cold . 485 
Air. 
0 
Dead frog, 
0 
Living fro, 
0 
In 1 
— 
7 of 
671 
2 
IOZ 
72 
68 
3 
IOO 
722 
69 1 
4 
IOO 
73 
70 
2 5 
95 
81 1 
7^1 
The thermometer being introduced into the ftomach, the 
internal heat of the animals was found to be the fame with 
that at the furface. 
From hence it appears, that the living frog acquired heat 
more {lowly than the dead one. Its vital powers muft, there- 
fore, have been adtive in the generation of cold. 
To determine whether the cold produced in this inftance de- 
pended folely upon the evaporation from the furface, increafed 
by the energy of the vital principle, a living and dead frog 
were taken at 75% and were immerfed in water at 93 0 , the 
living frog being placed in fuch a fituation as not to interrupt 
refpiration* 
/ 
Dead frog. , 
Living frog. 
c 
In 1 
85 
81 
2 
88 f 
85 
n 
90 1 
87 
5 
91 1 
89 
6 
91! 
89 
8. 
91 i 
00 
Thefe experiments prove, that living frogs have the faculty 
of refilling heat, or producing cold, when immerfed in warm 
water: and the experiments of Dr. fordyce prove, that the 
human body has the fame power in a moift as well as in a dry 
* In the above experiment the water, by the cold frogs and by the agitation 
which it fuffered during their immerfion, was reduced nearly to 9i°|. 
