Page 250 - My FlipBook

246 PATHOLOGICAL CONDITIONS.

readily and rapidly decomposed, so that the acid be-
comes again free to attack, with similar results, the
subjacent parts. The topical application of arsenic is
liable to be followed by constitutional effects.
All dentists are aware of the fact that a tooth-pulp
may be destroyed by arsenic, through a wall of con-
siderable thickness. To accomplish this, the agent
must in some way penetrate the substance of the
dentine; and its vitality is destroyed so far as it is
thus penetrated; indeed, the vitality of the whole

crown of the tooth, both dentine and pulp, is often
destroyed by the use of this remedy, applied even to
a small cavity. Exalted sensibility of dentine is
subdued by this agent, more by its devitalizing than
through its chemical energy. It is soluble in creosote
and similar oils, and, to a considerable extent, in
alcohol and water. It is absorbed much more rap-

idly when applied in solution than in solid ; and the
more vascular the dentine, the more rapid and exten-
sive will be the absorption ; and on this account there
is great risk in applying it to the teeth of young per-
sons, or to any teeth that are highly wanting in den-
sity ; indeed, it will destroy the vitality of very dense
teeth. The manner in which it passes into the den-
tine, is not very definitely understood. It is very
certain, however, that in more highly organized
parts, it is carried through by the circulation, and