_Of the Composition and close Connection of Parts in the Human Body._
The human body is composed of solids and fluids; these are so closely,
and so intimately combined with each other, that we find upon a physical
enquiry and examination, they are scarce separable. They aid and give
action to each other, and life depends not on each singly, but on the
united, and on the separate spur, and on the soul of activity each gives
to the other: Their substances form the body, and their action produces
the operation of the mind.
Whilst every thing moves free and agreeable to the talk prescribed by
nature, the automaton is in a state of health; body and mind enjoy peace
and tranquility. So closely are body and mind in the most perfect bond
of friendship, that they share pleasure and pain sympathetically with
each other; and reciprocally contribute to each other’s welfare.
With what satisfaction is the mind continually engaged to give pleasure
to the body! and with what alacrity are for ever the Members ready to
obey the will! Happy harmony, by which we so wonderfully exist!
The _solids_ are the canals and springs of life, and the _fluids_, which
circulate in those canals, nourish them, and set the springs in action.
By the _solids_ we understand,
1st The _bones_; the frame and support of our wonderful structure.
2dly. _Gristles_ or _cartilages_; which cover the ends of the bones, in
order to make them move with ease and agility.
3dly. _Muscles_; the fleshy parts, which by a nervous sensation, are
induced, either voluntarily or involuntarily, to contract or dilate
themselves, in order to give motion to the various parts of our body, to
which they are fastened or destined to move.
4thly. _Tendons_; the chords as it were, by which the muscles are
fastened to the bones, so as to make them follow the contraction of the
muscles.
5thly. _Ligaments_; the chords by which the bones are connected with
each other, and which give a firmness to their contact and articulation.
6thly. _Arteries_; the canals which transport the blood from the heart,
to all the parts of the body.
7thly. _Veins_; the canals which carry the blood from the remotest
arteries (in the most minute parts of the body) back again to the heart,
for a new rotation of the blood.
8thly. _Lymphatic Vessels_; which are small cellular canals, that convey
the lymph in different parts of the body.
9thly. _Glands_; which are kernels formed to _secrete_ or separate
various humours from the blood.
10thly. _Nerves_; these are medullary branches springing from the brain,
and distributed in the most minute parts of the body; ordained to give
the act of sensation, as the soul of animal activity.
11thly. _Hair_ and _nails_; these are a horny substance, and
appropriated either for defence or warmth of the different parts where
they are placed.
The _fluids_; are, 1st. _Blood_; which is circulated in the arteries and
veins, and is the nutriment and source of life.
2dly. The different humours separated by the glands from the blood; of
which there are many, as the _lymph_, _serum_, _spittle_, _seed_,
_chyle_, _urine_, _gall_, &c. appropriated to different uses, as
hereafter will be described.
3dly. _Fat_, and _marrow_ in the bones; which are designed not only as a
store of nourishment, but to lubricate and warm the parts where they are
lodged.
These are the principal materials which compose our wonderful machine.
There are various other parts mentioned by Anatomists, both solids and
fluids; but as this is designed only to give a universal idea of the
most material parts of the structure of this stupendous fabric, we will
let this definition suffice, and now consider with what order the
principal organs of life act, either in consort, or in opposition to
each other.
-------------------------------------------