i B4 Mr. Cruikshank's Experiments on the Nerves 
think fully proved by this experiment, was a circumstance to 
me, then, unexpected and unthought of. 
EXPERIMENT VI. 
April 19th, I divided the spinal marrow of a dog, between 
the last vertebra of the neck and first of the back. The 
muscles of the trunk of the body, but particularly those of the 
hind legs, appeared instantly relaxed ; the legs continued 
supple, like those of an animal killed by electricity. The heart, 
on performing the operation, ceased for a stroke or two, then 
went on slow and full, and in about a quarter of an hour after, 
the pulse was lbo in a minute. Respiration was performed by 
means of the diaphragm only, which acted very strongly for 
some hours. The operation was performed about a quarter of 
an hour before twelve at noon ; about four in the afternoon the 
pulse was ninety only in a minute, and the heat of the body 
exceedingly abated, the diaphragm acting strongly, but irre- 
gularly. About seven in the evening, the pulse was not above 
twenty in a minute, the diaphragm acting strongly, but in re- 
peated jerks. Between twelve at night and one in the morn- 
ing, the dog was still alive ; respiration was very slow, but the 
diaphragm still acted with considerable force. Early in the 
morning he was found dead. This operation I performed from 
the suggestion of Mr. Hunter : he had observed in the hu- 
man subject, that when the neck was broke at the lower part, 
(in which cases the spinal marrow is torn through), the patient 
lived for some days, breathing by the diaphragm. This ex- 
periment showed, that dividing the spinal marrow at this place 
