t52 On (he Torpidity of Monkeys and other Animals, 



tried by the thermometer, increased with the frequency of 

 respiration, so that by half-past nine o'clock il was perfect- 

 ly awake. 



Convinced by this experiment that the action of cold, 

 although it increases almost insensibly, occasions pain to 

 animals in a state of torpidity, I returned the monkey to its 

 bed of hay. I tried to make it walk upon the carpet, but it 

 could not use its hind legs, which were torpid from having 

 been so far from the chest. 



On the 20th of February, at seven o'clock in the morn- 

 ing, I tried another experiment with the largest torpid mon- 

 key : I placed it outside my window in a vessel surrounded 

 by ice and muriate of lime. This mixture produced so in- 

 tense a cold in the receiver, that the thermometer I placed 

 iu it fell to 7° below zero. 



This sudden transition did not excite any sudden convul- 

 ;jive movements in the monkey : in half an hour I observed 

 it to give sions of pain. I observed increasing signs of re- 

 spiration and expiration, which must have fatigued it mucb. 

 It was eleven o'clock, however, before it was completely 

 awake. The cold continued very sharp, and it tried to 

 escape from it several tin>es, by moving from side to side 

 in great pain throughout the night. 



1 visited it several times, and found it always trembling i 

 jts eyes were half closed. It did not sleep, however, al- 

 though I left it exposed to the same cold till nine o'clock 

 next morning. I am convinced that a sharper cold would 

 in a short time have plunged it into that lethargy which is 

 followed by death, when no assistance is given to prevent it. 



I have here detailed only the general outlines of my ob- 

 servations upon monkeys. In a subsequent menjoir 1 shall 

 publish my experiments upon bats, hedgehogs, Sec. : and 

 I flatter myself that their result will be an accurate know- 

 Jege of the causes which plunge animals into a torpid sleep. 



LI. The 



