e of the electric fluid is, we are ignorant; some
galvanic experiments have led me to suppose that it may be
hydrogen, which when combined with caloric appears in the form of
gas, but when pure, or perhaps in a different state, may be
capable of passing through solid bodies in the form of
electricity.

Having given this short view of the human body, considered as a
machine composed of bones, muscles, and nerves, I shall proceed to
state the different subjects which I shall consider in this
course. It is extremely difficult to begin a course like this; for
we must either enter abruptly into the middle, or the outset must
be in some measure tedious and dry. I have chosen however rather
to hazard the latter appellation, with respect to this lecture,
than to enter more abruptly into the subject, in order to make it
more entertaining. As we proceed, I trust you will feel an
increasing interest in the subject; and, I think I may venture to
promise, that this will be found the least entertaining lecture in
the course. The subjects will be illustrated by experiments, in
order to render the deductions more striking.

I shall next proceed to consider the phenomena of respiration, and
animal heat; after which I shall explain the circulation of the
blood; and the phenomena of digestion and nutrition. I shall then
examine, more minutely than has been done in this lecture, the
connexion of man with the external world, which will lead to a
discussion of the different senses; vision, hearing, smelling,
tasting, and feeling.

When these subjects have been discussed as fully as our time will
allow, I shall examine, at considerable length, the manner in
which the powers that support life, which have been improperly
called by physiologists, the nonnaturals, act upon the body. This
will naturally lead to a fuller explanation of the system which I
have attempted to defend, in my lecture on health. And, after I
have fully explained the laws by which the irritable principle is
regulated, I shall proceed to show, how those variations from the
healthy state, called diseases, are produced; I shall point out
the difference that exists between the debility which is brought
on by the diminished action of the powers which support life, and
that which results from their too powerful action; I shall then
inquire into the nature of diseases of increased excitement; and
after having shown how the undue action of the powers which
support life, opera