sources of the sympathies of our organs; and, in short, the explanation
of every thing obscure in physiology, pathology, or expression,
was sought for in the influence of this class or system of nerves.
As the nerves called sympathetic are universally spread over the
body, there was no consent of parts or sympathy, from the blush of
passion to the act of sneezing, but was readily assigned to the
influence of some branch or network of this system of nerves ; and
although this opinion was universally received in all countries, it
had no foundation in truth.
While there is every probability that the sympathetic system,
or, as it is sometimes called, the ganglionic system of nerves,
ministers to certain operations of the animal economy, it has no
control over the muscular frame, either in the performance of the
voluntary motions, or during that influence of the mind upon the
bodily frame which we call passion.
In the volume of the Philosophical Transactions for the year
1821, there is a paper of mine which proves that, independent of
the common nerves which bestow sensibility, and also of the
branches of the sympathetic nerve, there is a nerve which extends
from one point over the whole face, possessed of totally different
powers. It is there also proved by observations made on the effects
of the accidental injuries and diseases of these nerves, and also by
experiments on animals, that the motions of breathing and speaking,
as far as they regard the face, and all the indications of emotion
in the countenance of man, or of passion in brutes, are produced
solely through the influence of this nerve. It is also shown there,
that the singular course of this nerve, apart from the common
nerves of the face (a circumstance always known, but not hitherto
explained), is for the purpose of its being associated with a set of
nerves of the same class and function with itself.
Although this nerve be the source of all those Varying emotions
of the countenance which indicate the condition of the mind, yet
I have called it the respiratory nerve of the face, for reasons which
I entreat my reader’s patience until I explain; and this is the more
necessary, since we shall find that the whole extended apparatus
of respiration is the instrument of expression, as it is of voice and
speech.
Some account of the author's discoveries in the nervous system, as
directing the actions of breathing, speaking, and expression*.
In the face we have an opportunity of observing the subservience
of the nerves to the different uses of the parts. The
human countenance performs many functions: in it we have combined
the organs of mastication, of breathing, of natural voice and
speech, and of expression; some motions are performed directly by
* This will be found further illustrated in the Philosophical Transactions, vol. for
the years 1821, &c.