Page 42 - My FlipBook

38 INTRODUCTION.

on the ends. He had not used them in the mastica-
tion of his food, for his molar teeth were all good,
and sufficient for this purpose; and moreover it had
been impossible for him to use them in mastication,
since he could not bring them together; and he had
not been in the habit of putting any hard substance
between them.

The Cause.—The cause of this affection, like that
of denuding, is not well understood. It is supposed,
however, to be induced by an acid contained in the
mucus. If this supposition is correct, it must be
some -acid with whose nature we are but little, if at
all, acquainted; or, if any ordinary acid, it certainly
must be modified by very peculiar circumstances, so
that it effects a solution of both the animal and earthy

constituents. The surface upon which it acts is always
perfectly smooth and polished, never presenting that
roughened and abraded appearance caused by the ac-
tion of any ordinary acid upon enamel or dentine.
And again, if this affection results from the operation
of an acid in the mucus, why does not this acid, to
some extent at least, affect the teeth at other points?
Such is not the fact; and caries that has previously
commenced at other points on the teeth, does not
progress more rapidly during the existence of this
disease, than before ; but it certainly would, if there
were a large quantity of acid in the mucus.