ecomes more exquisite when its organ is
defended from the action of external bodies; it is on this account
that the cuticle becomes so sensible under the end of the nail, which
defends it from the action of external objects; and when part of the
nail is taken away, we can scarcely bear to touch any thing with this
newly exposed part of the skin.

When we place our fingers upon the surface of any body, the first
sensation we experience is that of resistance, after which the other
properties are perceived in a natural order; such as heat or cold,
moisture or dryness, motion or rest, distance, and figure or shape.

With respect to the diseases of this sense, it is very seldom that it
becomes too acute over the whole body; though it frequently does so
in particular parts, which may arise from the cuticle being too thin
or abraded, or from an inflamed state of the part.

It however becomes sometimes obtuse, and indeed almost abolished over
the whole body; and this takes place from compression of the brain,
and various affections of the nervous power. This diminution is
called anaesthesia. The touch becomes deficient, and indeed almost
abolished, when the cuticle is injured by the frequent application of
hot bodies, or acrid substances: thus the cuticle of the hands of
blacksmiths and glassblowers is generally so hard and horny, that
they can take up and grasp in their hand pieces of redhot iron with
impunity.

We generally refer pain to this sense, though it may arise from too
violent an impression made upon any of the organs of sense.

Pain is an unpleasant sensation, which the mind refers to some part
of the body, and very accurately, if any part of the surface is
affected, but less so, if it arises from the affection of an internal
part. The sensation of pain may arise from any thing which tends to
injure the structure of the body, whether that be internal or
external; so that it serves as a monitor to put us on our guard, and
to induce us to remove any thing which might be injurious to us. This
sensation is produced by any thing which punctures, cuts, tears,
distends, compresses, bruises, corrodes, burns, or violently
stimulates any part of the body.

A moderate degree of pain in any part excites the action of the whole
body; a greater quantity of blood and nervous energy is determined to
the part. A still greater degree of pain brings on inflammation and
its consequences, and if it be intense, it will bring on fe