360 INFLUENCE OF THE BRAIN ON THE ACTION OF THE HEART. 



The truth of this conclusion was ascertained by the follow- 

 ing experiment. 

 Exp. I. On a Exp. 1. I divided the spinal marrow of a rabbit in the 

 muniMdon^cut^P^^® between the occiput and atlas, and having made an 

 off, and respi- opening into the trachea, fitted into it a tube of elastic 

 "^^"tifickir"' S""*j *o which was connected a small pair of bellows, so 

 constructed, that the lungs might be inflated, and then al- 

 lowed to empty themselves. By repeating this process 

 once in five seconds, the lungs being each time fully in- 

 flated with fresh atmospheric air, an arti^cial respiration 

 was kept up. I then secured the blood vessels in the neck, 

 and removed the head, by cutting through the soft parts 

 above the ligature, and separating the occiput from the 

 atlas. The heart continued to contract, apparently with as 

 piuch strength and frequency as in a living animal. I exa- 

 mined the blood in the different sets of vessels, and found 

 it dark coloured in the venae cavjc and pulmonary artery, 

 and of the usual florid red colour in the pulmonary veins 

 and aorta. At the end of twenty-five minutes from the 

 time of the spinal marrow being divided, the action of the 

 heart becaipe fainter, and the experiment was put an end to. 

 No urine With a view to promote the inquiry instituted by the 



lecreted. society for promoting the knowledge of animal chemistry 



respecting the influence of the nerves on the secretions *, 

 I endeavoured to ascertain, whether they continued after 

 the influence of the brain was removed. In the commence- 

 ment of the experiqfient I emptied the bladder of its con^ 

 tents by pressure; at the end of the experiment the bladder 

 continued empty. 



This experiment led me to conclude, that the action of 

 the heart might be made to continue after the brain was re- 

 moved, by means of artificial respiration) but that under 

 these circumstances the secretion of urine did not take 

 place. It appeared, however, desirable to repeat the ex- 

 periment on a larger and less delicate animal; and that, 

 in doing so, it would be right to ascertain whether under 

 these circumstances the animal heat was kept up to the na« 

 tural standard* 



♦ Philosophic^ Transactions for J 809. Journal vol. xxvi, p. 135. 



Evvt* 



