18 ON THE INFLUENCE 



found to be as completely destroyed, as if the 

 head had been actually removed. 



Under these circumstances, if the artificial 

 respiration be kept up until the effects of the 

 poison cease, as the animal recovers his sen- 

 sibility, so does he also recover the power of 

 generating heat; but it is not till the nervous 

 energy is completely restored, that heat is pro- 

 duced in sufficient quantity to counteract the 

 cold of the surrounding atmosphere.* 



In the experiments formerly detailed, as well 

 as in those just mentioned, I observed that the 

 blood underwent the usual alteration of colour 

 in the two systems of capillary vessels, while car- 

 bonic acid was evolved from the lungs at each 

 expiration ; and hence I was led to believe, that 

 the respiratory function was performed nearly as 

 under ordinary circumstances, and that the usual 

 chemical changes were produced on the blood. 

 It appeared, however, desirable to obtain some 

 more accurate knowledge on these points, and I 

 have therefore instituted a series of experiments, 

 for the purpose of ascertaining the relative quan- 

 tities of air consumed in breathing, by animals 

 in a natural state, and by animals in which the 



* The poison employed in this experiment, should be the 

 essential oil of almonds, or some other, the effects of which 

 speedily subside. If the woorara be employed, so long a 

 time elapses before the poison ceases to exert its influence, 

 that it becomes necessary that the experiment should be 

 made in a high temperature, otherwise'the great loss of heat 

 which takes place, is sufficient to prevent recovery. 



