THE LOWER SENSES.
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likeness to the instance of Taste is very striking An
extremely small quantity of the irritant is agreeable as
stimulation, but only to the dulled and blunted nervous
centres of adults : while even with them a slight excess
brings on the painful and destructive degree of action.
Furthermore, each of these stimulants, when inhaled in lanre
quantities, exercises a destructive action upon the tissues of
the lungs; while, if swallowed in excess, they will prove
injurious, as we have already seen, to the coats of the
stomach and intestines. So that we have here a double
instance of the establishment of an organic consensus, the
pungency at once warning us off from inhaling the irritant
vapour in any large amount, and deterring us from making
any further experiment by putting the body whence the
vapour arises into our mouths. Children and dogs are
generally sufficiently instructed by the nose not to eat any¬
thing on which mustard or pepper has been spread : and the
violent irritation caused by large volumes of pungent vapour
soon urges us to remove the smelling bottle, or to rush from
the loaded atmosphere into the open air, as the case may be.
Passing on to the pure olfactory sensibility, we shall find
it convenient to take separately the two classes of sensations
which yield indications of the probable effects upon the
stomach and the lungs respectively of bodies which give rise
to smell. In the first of these two classes we notice that
the scent of cooked meats and other relishes is pleasing so
long as we are hungry, but becomes distasteful as soon as
we have eaten to repletion. This shows a sympathy with
the stomach exactly analogous to that of Taste. Similarly,