i88 Mr. Cruikshank's Experiments on the Nerves 
a hundred and twenty in the same time. Finding that respi- 
ration went on very easily without the diaphragm, in about 
a quarter of an hour after dividing the axillary plexus of each 
side, I divided the spinal marrow, as in experiment vi. The 
whole animal took the alarm, all the flexor muscles of the 
body seemed to contract, and instantly to relax again ; he 
died as suddenly, as if the spinal marrow had been divided in 
the upper part of the neck. I then opened the chest, and 
found the heart had ceased its motion ; I immediately intro- 
duced a large blowpipe into the trachea, below the cricoid 
cartilage, and inflating the lungs, imitated respiration. The 
heart began to move again, and in about three minutes was 
beating seventy in a minute. I recollected that there was still 
a communication between the brain, and the thoracic and ab- 
dominal viscera, that the par vagum and intercostals were en- 
tire, and turning to the carotids, divided the nerves. I then 
went on inflating the lungs as before ; the heart, which had 
stopped, began to move again, beat seventy in a minute, and 
continued so for near half an hour after the animal had seem- 
ingly expired. These appearances were not confined to the 
neighbourhood of the heart ; one of the gentlemen who as- 
sisted me, cried out once, that he felt the pulse in the groin. 
I now ceased to inflate the lungs, and presuming that I could 
easily reproduce the heart's action, allowed three minutes to 
elapse. On returning to inflate the lungs, I found the heart 
had now lost all power of moving ; and that irritating the ex- 
ternal surface with the point of a knife, did not produce the 
smallest vibration. I then irritated the phrenic nerves with 
the point of a knife ; the diaphragm contracted strongly as 
often as the nerves were irritated, I irritated the stomach 
