ver,
convulsions, delirium, fainting, and even death.

The endurance of pain depends much on the strength of mind possessed
by the patient, which, in some instances, is such, that the most
violent pains are patiently endured; while in other instances, the
slightest can scarcely be born.

It is a curious circumstance, that a moderate degree of pain, when
unaccompanied by fever, often tends to render the understanding more
clear, lively, and active. This is confirmed by the experience of
people labouring under gout. We have an account of a man who
possessed very ordinary powers of understanding, but who exhibited
the strongest marks of intelligence and genius in consequence of a
severe blow on the head; but that he lost these powers when he
recovered from the effects of the blow. Pechlin mentions a young man,
who during a complaint originating from worms, possessed an
astonishing memory and lively imagination, both of which he nearly
lost by being cured. Haller mentions a man who was able to see in the
night, while his eyes were inflamed, but lost this power as he got
well. All these facts show, that a certain action or energy is
necessary for the performance of any of the functions of the body or
mind; and whatever increases this action will, within certain limits,
increase those functions.

Feeling is by far the most useful, extensive, and important of the
senses, and may be said indeed to be the basis of them all. Vision
would be of very little use to us, if it were not aided by the sense
of feeling; we shall afterwards see that the same observation may be
applied to the other senses. In short, it is to this sense that we
are indebted, either immediately or indirectly, for by far the
greatest part of our knowledge; for without it we should not be able
to procure any idea with respect to the magnitude, distance, shape,
heat, hardness or softness, asperity or smoothness of bodies; indeed,
if we were deprived of this sense, it is difficult to say whether we
should have any idea of the existence of any external bodies; on the
contrary, it seems probable that we should not.

LECTURE VI.
TASTE AND SMELL.

From the sense of touch we proceed naturally to that of taste, for
there seems to be less difference between these two senses than
between any of the others. The sense of taste appears to be seated
chiefly in the tongue; for any sweet substance, such as sugar,
applied to any other part of the mouth, scarcely excites