4$8 Dr. Philip's additional experiments on the 
more different than this string of ganglia and a nerve, such 
as it passes directly from the brain and spinal marrow to the 
muscles of the trunk or limbs. It may also be worth remark- 
ing, that the nerves sent off from ganglia, have a very diffe- 
rent appearance from those coming directly from the brain 
and spinal marrow. Recherches Physiques sur la vie et la mort, 
&c. par M. Bichat. 
The question has been much agitated, why the will has no 
influence over the muscles of involuntary motion. It has 
been supposed that the ganglia intercept its influence, but we 
see in the above experiments, that the ganglia do not inter- 
cept the influence of either stimuli or sedatives applied to the 
nervous system. We can be at no loss to account for our 
want of power over these muscles, when we consider, that 
in their ordinary action, they obey stimuli over which we 
have no influence; and that, at all times, we neither see 
nor are otherwise conscious of their motions, and consequently 
cannot direct them. 
I have endeavoured by the following experiments to ascer- 
tain, whether the power of the blood vessels is as independent 
of the nervous system, as that of the heart ; and whether 
this system possesses over them the same kind of influence, 
as over the heart. 
These experiments were made on the capillaries of the 
frog, which, from the extent and transparency of the web 
of its hind feet, and from its great tenacity of life, appeared 
the best subject for such experiments. It has been ques- 
tioned, how far inferences drawn from experiments made on 
cold blooded animals, can be supposed to apply to those of 
