and Spinal Marrow of living Animals . 187 
muscles of respiration, and reduced the animal to the state of 
one hanged ; whereas in dividing it lower, we still left the 
phrenic nerves, and allowed the animal to breathe by his dia- 
phragm. If this opinion be well founded, though dividing 
the spinal marrow in the lower part of the neck does not kill 
instantly, whilst the phrenic nerves are untouched; yet if I 
divide the phrenic nerves first, and then divide the spinal mar- 
row in the lower part of the neck, the consequence, I said, 
will be the same, as if I had divided it in the upper part. 
EXPERIMENT VIII. 
By detaching the scapulae of a dog from the spine, and 
partly from the ribs, I got at the axillary plexus of nerves, on 
both sides, from behind. I separated the arteries and veins 
from the nerves, and passed a ligature under the nerves, close 
to the spine. I thought I could discern the phreniG nerves, 
and instantly divided two considerable nerves going off from 
each plexus. The action of the diaphragm seemed to cease, 
and the abdominal muscles became fixed, as if they had been 
arrested in expiration, the belly appearing contracted. His 
respirations were now about twenty-five in a minute, the 
pulse beating a hundred and twenty. As I was not willing to 
trust the experiment to the. possibility of having divided only 
one of the phrenics (which I afterwards found was really 
the case), and some different nerve instead of the other, after 
carefully attending to the present symptoms, I divided all the 
nerves of the axillary plexus, of each side. The ribs were 
now more elevated in inspiration than before ; respirations 
were increased to forty in a minute ; the pulse still beating 
Bb2 
