rane
which envelopes the nervous papillae of the tongue, and serves as a
cuticle, should neither be too thick nor too thin, too dry nor too
moist. It is necessary likewise that the qualities of the saliva be
natural; for alterations in the nature of this liquor affect very
much the sense of taste; if it is bitter, which sometimes happens in
bilious complaints, all kinds of food have a bitter taste; if it is
sweet, the food has a faint and unpleasant flavour; and if it is
acid, the food too tastes sour.

This sense is seldom observed to be too acute, unless from a vitiated
state of the cuticle, or membrane, which covers the tongue: if this
has been abraded or ulcerated, then the substances applied to the
tongue are more sensibly tasted; in many instances, however, they do
not produce an increased sensation of taste, but only of pain.

The sense of taste, as well as of touch, may become deficient, from
various affections of the brain and nerves; this, however, is not
often the case. Some persons have naturally a diminished sense of
taste, and this generally accompanies a diminished sense of smell.
This sense is frequently diminished in sensibility from a deficiency
of saliva, as well as of the proper moisture of the tongue. Hence, in
many diseases, it becomes defective, such as fevers, colds, and the
like; both from a want of the proper degree of moisture, and from
defect of appetite, which, as was before observed, is necessary to
the sense of taste.

The sense of taste is often diminished by a thickened mucous covering
of the tongue, which prevents the application of substances to its
nervous papillae. This mucous covering arises from a disordered state
of the stomach, as well as from several other affections of the body:
hence physicians inspect the tongue, that they may be able to judge
of the general state of the body; and next to the pulse, it is
undoubtedly the best criterion that we have, as it not only points
out the nature and degree of several fevers, but likewise, in many
instances, the degree of danger to be apprehended.

Having examined the sense of taste, I shall now proceed to consider
that of smell; the use of which, like taste, is to enable us to
distinguish unwholesome from salutary food; indeed, by this sense, we
are taught to avoid what is prejudicial before it reaches the sense
of taste, to which it might be very injurious; and thus we are
enabled to avoid any thing which has a putrid tendency, w