364 



Exp. 6. On a 



Urge rabbit. 



Comparative 

 experiment on 

 a smaller. 



INFLUENCE OP THE BRAIN ON THE ACTION OF THE HEART. 



During the experiment, the blood in the femoral artery 

 "was seen to be of a bright florid colour, and that in the 

 femoral vein of a dark colour, as usual. 



The rabbit voided urine at the commencement of the 

 experiment; at the end of the experiment no urine was 

 found in the bladder. 



Exp. 6. I procured two rabbits of the same colour, but 

 one of them was about one fifth smaller than the other. I 

 divided the spinal marrow of the larger rabbit between 

 the occiput and atlas. Having secured the vessels in the 

 neck, and removed the head, I kept up the circulation by 

 means of artificial respiration as in the former experiments. 

 The respirafions were made as nearly as possible similar to 

 natural respirations. 



In 23 minutes after the spinal marrow was divided, the 

 pulse was strong, and 130 in a minute: the ball of the ther- 

 mometer being placed among the^ viscera of the abdomen, 

 the mercury stood at 96^. 



At 34 minutes the pulse was 120 in a minute: the beat 

 in the abdomen was 95'^, 



At the end of an hour the pulse could not be felt, but 

 on opening the thorax the heart was found acting, but 

 slowly and feebly. The heat in the abdomen was 91**; aud 

 between the lobes of the right lung 88**. 



During the experiment, the blood in the arteries and 

 veins was seen to have its usual colour. 



In this therefore, as in the preceding experiments, the 

 heat of the animal sunk rapidly, notwithstanding the con- 

 tinuance of the respiration. In order to ascertain whether 

 any beat at all was generated by this process, I made the 

 following comparative experiment. The temperature of 

 the room being the same, I killed the smaller rabbit by di- 

 Tiding the spinal marrow between the occiput and atlas. Jn 

 consequence of the difference of size, cceteris paribus y the 

 heat in this rabbit ought to diminish more rapidly than in 

 the other; and I therefore examined its temperature at the 

 end of 52 minutes, considering that this would be at least 

 equivalent to examining that of the larger rabbit at the end 

 of an hour. At 52 minutes from the time of the smaller 

 rabbit being killed, the heat among the Tiscera of the ab- 

 domen 



