DR. PHILIP ON THE POWERS OP LIFE. 
347 
although, in their usual functions, the heart and vessels, like the other muscles of 
involuntary motion, obey neither of these organs, but agents peculiar to them- 
selves*. 
Thus it appeared that the ganglionic, like the cerebral and spinal nerves of motion, 
may administer towards the contraction of the muscular fibre, unless, what I conceive 
to be more probably the case although not yet ascertained, branches of the latter 
nerves are bound up in the same sheath with the ganglionic nerves, as we shall find 
there is reason to believe is the case with respect to the nerves of sensation. Phy- 
siology has been much indebted to the experiments of Sir Charles Bell, M. Ma- 
jendie and Mr. Mayo, from which it appears that the nerves of motion and those of 
sensation, although often bound up in the same sheath, are distinct nerves having 
different origins. 
What are the functions which are peculiar to the ganglionic nerves in the sense 
in which I use that term ? 
This question is answered respecting one of the most important of the vital func- 
tions, the process of secretion, in papers published in the Philosophical Transactions 
for 1815 and 1822, and republished in the last edition of my Inquiry into the Laws of 
the Vital Functions. 
It appears from the experiments detailed in those papers that when part of the 
eighth pair of nerves in their passage along the neck is removed, or these nerves are 
divided and one end of either portion is raised from its place, the secretion of gastric- 
juice soon begins to fail in its properties ; and if the animal survives for a certain 
time, the contents of the stomach are found not only undigested but quite dry, proving 
that there had been no secretion from it whatever for some time. 
From these experiments we also learn how it has happened that such various ac- 
counts of the effects in the stomach of dividing the eighth pair of nerves is given by 
different experimentalists ; because it was found that digestion was more or less com- 
pletely interrupted in proportion as the divided ends of the nerves were kept at a 
considerable distance from each other. Even when the distance was a quarter of an 
inch, provided the divided ends were no otherwise displaced than in consequence of 
the retraction of the nerve on its division, digestion, although more or less deranged, 
was not interrupted, a subject to which I shall have occasion to recur. Now as this 
was a point which never particularly demanded attention, accident must always have 
more or less influenced the result. 
But secretion is not the only vital function that is influenced by the division and 
separation of the divided ends of the eighth pair of nerves in the neck. It appears 
from experiments detailed in a paper, published in the Philosophical Transactions 
for 1827 and republished in my treatise On the Nature of Sleep and Death, that, 
under such circumstances, all the assimilating functions are so deranged that in 
* See two papers published in the Philosophical Transactions for 1815, and republished in my Inquiry into 
the Laws of the Vital Functions. 
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