436 Dr. Philip’s additional experiments on the 
remarkably from any one part, a circumstance which par- 
ticularly corresponds with the result of the foregoing experi- 
ments. 
From the same facts we explain, why the heart is stimulated 
through the nervous system after the power of this system 
is so far weakened as no longer to convey the effect of the 
stimulus to the muscles of voluntary motion. As these obey 
stimuli applied to only one part of the nervous system, if the 
change in this partis not strong enough to produce the effect, 
it cannot be assisted by any other. Thus I have found by 
experiment, that a blow which affects the brain generally, 
without materially injuring it, produces comparatively little 
effect on the muscles of voluntary motion, because no one 
part suffers greatly, but it produces a great effect on the 
heart, because it feels the sum of all the impressions. The 
nervous system, therefore, may be so far exhausted as not to 
admit of the vivid impressions necessary to excite the muscles 
of voluntary motion, and yet capable of those which influence 
the heart. 
It appears from the foregoing experiments, that the heart 
is influenced by every part of the nervous system ; and in a 
former paper I pointed out why we have reason to believe 
that the intestines obey the same laws with the heart, although 
this cannot be so directly proved. From the situation of the 
ganglia compared with the whole of the experiments here 
alluded to, I think we cannot help believing, that their office 
is to combine the influence of the various parts of the nervous 
system, from which they receive nerves, and to send off 
nerves endowed with the combined influence of those parts. 
