432 Dr. Philip’s additional experiments on the 
through any considerable portion of the brain immediately 
accelerated it. 
Exp. 10. I laid open the cervical part of the spine of a 
rabbit, rendered insensible by a blow on the occiput, and re- 
peatedly passed the wire transversely through the spinal 
marrow, without being able at all to affect the motion of the 
heart ; but on passing the wire longitudinally, so as to bring 
it in contact with a larger portion of the spinal marrow, I 
found the motion of the heart immediately accelerated. On 
the same principle, when the wire was made to wound many 
minute portions of the brain and spinal marrow in quick suc- 
cession, the action of the heart was increased. In another 
rabbit, I divided the spinal marrow at the occiput without at 
all affecting the heart. 
Mr. Clift, in an account of experiments on the Carp, pub- 
lished in the Philosophical Transactions for this year, ob- 
serves, that on dividing the spinal marrow at the occiput, the 
action of the heart was greatly accelerated for a few beats ; 
but he divided the spinal marrow while the animal retained 
the power of the muscles of voluntary motion, which never 
fail to be called into action by wounding it, and whose action, 
by increasing the flow of blood, always accelerates the motion 
of the heart.* 
Thus we see that neither chemical nor mechanical stimuli 
applied to the nervous system, affect the action of the heart, 
* It is particularly satisfactory to me that Mr. C lift, on repeating my expert" 
ment, in which the spinal marrow was destroyed by a hot wire, found the same result 
in the carp, which I had done in rabbits and frogs. He did not ascertain whether 
the circulation continued after the destruction of the spinal marrow, but from this 
occasioning little or no diminution in the action of the heart, we can have little doubt 
of the continuance of the circulation. 
