366 



INFLUENCE OF THE BRAIJf ON THE ACTION OP THE HEART, 



At 45 minutes it had fallen to 68°. 



At the end of an hour the heat in the rectum was 96|. 



At an hour and a quarter it was 95®. 



At an hour and a half it was 94^. 



At an hour and forty minutes the heat in the rectum waa 

 93°, and in the bag of the pericardium 90^. 



The following table will shew the comparative tempera- 

 ture of the two animals at corresponding periods. 



Table of their 



comparative 



temperatures. 



Time. 



Before the 7 



experiment. 5 



SOmin.aft. 



45 



60 



75 



90 



100 



Rabbit with artificial 

 respiration. 



Therm, in 

 the Rectum. 



100| 

 97 

 95| 

 94 

 92 

 91 

 904 



Therm, in the 

 Pericardium. 



871 



Dead Rabbit. 



Therm, in 

 the Rectum 



lOOi 

 99 

 98 

 96i 

 95 

 94 

 93 



Therm, in the 

 Pericardium. 



901 



The production In this experiment, the thorax, even in the dead animal, 

 of animal heat cQQig^ jPQre rapidly than the abdomen. This is to be ex- 

 dep'?nd"on re- plained by the diiference in the bulk of these two parts. 

 spiration. fhe rabbit in which the circufation was maintained by 



artificial respiration cooled more rapidly than the dead 

 rabbit : but the diiference was more perceptible in the thorax 

 than in the rectum. This is what might be expected, if the 

 production of animal heat does not depend on respiration ; 

 since the cold air, by which the lungs were inflated, must 

 necessarily have abstracted a certain quantity of heat, par- 

 ticularly as its influence was communicated to all parts of 

 the body, in consequence of the continuance of respi- 

 ration. 

 Objection. It was suggested that some animal heat might have been 



generated, though so small in quantity as not to counter- 

 balance the cooling powers of the air thrown into the lungs. 

 It is difficult, or impossible, to ascertain with perfect ac- 

 curacy, what effect cold air thrown into the lungs would 



have 



