78 Dr. Philip’s experiments to ascertain the principle 
was opened under tepid water : but this was found to excite 
even stronger spasms than the air had done. 
What are the simple results of the foregoing experiments? 
The first set prove, that the power of the heart is independent 
of the brain and spinal marrow, for we find that it continues 
to perform its function after they are destroyed or removed, 
and that their removal is not attended with any immediate 
effect on its motions. The second set prove, that the action 
of the heart may be influenced by agents applied to any con- 
siderable portion either of the brain or spinal marrow. Itis 
as readily influenced by agents applied to the anterior part 
of the brain, as by those applied to the cervical part of the 
spinal marrow. This is what we should expect when we 
trace the various origins of its nerves. 
If it be said that the results of these experiments imply a 
contradiction, that we cannot suppose the power of the heart 
to be wholly independent of the brain and spinal marrow, 
and yet influenced by stimuli applied to them, the reply is, 
that such are the facts, of the truth of which any one may 
easily satisfy himself. Daily occurrences correspond with these 
facts. We rarely see the action of the heart destroyed by 
injuries of the brain and spinal marrow, unless they are such 
as interrupt respiration ; yet its action is constantly influenced 
by affections of the mind. 
On a closer examination of the phenomena of the nervous 
system, we shall find other similar difficulties. The experi- 
ments of M. le Gallois prove, in the most satisfactory 
manner, that a principal function of the spinal marrow is to 
excite the muscles of voluntary motion, and that it can per- 
form this office independently of the brain. It performs it 
