356 
DR. PHILIP ON THE POWERS OF LIFE. 
will find the circumstances detailed which led to the successful experiment, the result 
of which was publicly confirmed both in London and Paris ; and those who in the 
first instance ridiculed my expectations, joined me in stating that such is the 
fact. 
The cause of failure in my first experiments on this subject, was the circumstance 
of having made a wrong choice of the nerve on which I operated, which was a nerve 
of voluntary motion. 
It will appear on reflection that this was a wrong choice. Before we can expect 
that the nervous influence can be made to pass through any other conductor 
than that to which it belongs in the animal body, there must exist a powerful cause 
soliciting it to some particular point. In a muscle of voluntary motion there can 
be no such cause. The nervous influence is not attracted to the muscle, it is sent 
to it by an act of the sensorium, carried into effect by the powers of the nervous 
organs, which are subjected to its influence ; those organs which, on the one hand, 
prepare that influence, and those which, on the other, convey it when duly prepared*. 
The muscle is altogether passive till the influence is applied to it. But the case is 
wholly different with respect to many of the organs which contribute to the functions 
of the ganglionic system. We know from direct observation that in many of them, 
there is a cause continually operating, which solicits the nervous influence to them. 
In these organs the living blood and nervous influence cooperate in the functions 
of secretion and assimilation ; and it is an acknowledged fact, that when a determi- 
nation of blood to secreting organs takes place, there is in the same proportion 
an increase of their secreted fluids, a result which cannot arrive without a corre- 
sponding supply of nervous influence. Thus we know, as indeed we had reason 
to expect, that the presence of the living blood in the secreting organs solicits a pro- 
portionable supply of that influence ; and thus it was, that whereas, while I operated 
on the nerves of voluntary motion, my attempts were wholly fruitless, the very first 
attempt with the ganglionic nerves was crowned with success ; nor, since the repe- 
tition of the experiments in London and Paris, has the fact been questioned. 
If the facts I have stated be correct, we can have little doubt that the nervous in- 
fluence is of a nature similar to the inanimate agent which was substituted for it ; for 
to say nothing of the circumstance of the nervous influence being capable of existing 
in a texture different from that to which it belongs in the living animal, we cannot 
suppose that there are two distinct powers, the one of which is capable of all the 
effects of the other ; or I would rather say, that such a supposition amounts to a con- 
tradiction in terms, because as it is acknowledged that we know nothing of any 
principle of action but by its properties, it necessarily follows, that by these alone it 
can be distinguished. 
In discussing the nature of the nervous influence too much has been ascribed to elec- 
tric tests, which are referred to as if they possessed a power equal to that of chemical 
* See the second of my papers in the Philosophical Transactions for 1829. 
