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OF THE BONY PART OF A TOOTH. 51
That part of a Tooth which is bony, is nearly of the same
form as a complete Tooth ; and thence, when the Enamel is
removed, it has the same sort of edge, point, or points, as when
the Enamel remained. We cannot by injection prove that the
bony part of a Tooth is vascular : but from some circumstances
it would appear that it is so ; for the Fangs of Teeth are liable
to swellings, (s) seemingly of the spina ventosa kind, like other
bones ; and they sometimes anchylose with the socket by bony
and inflexible continuity, as all other contiguous bones are apt
But there may be a deception here, for the swelling
to do. (f)
may be an original formation, and the anchylosis may be from
the pulp that the Tooth is formed upon being united with the
socket. The following considerations would seem to shew that
the Teeth are not vascular : first, I never saw them injected in
any preparation, nor could I ever succeed in any attempt to
inject them, either in young or old subjects ; and therefore
believe that there must have been some fallacy in the cases
where they have been said to be injected. Secondly, we are not
able to trace any vessels going from the pulp into the substance
of the new-formed Tooth ; and whatever part of a Tooth is
formed, it is always completely formed, which is not the case
with other bones. But what is a more convincing proof, is
reasoning from the analogy between them and other bones,
when the animal has been fed with madder. Take a young
animal, viz. a pig, and feed it with madder, for three or four
weeks ; then kill the animal, and upon examination you will
find the following appearance : first, if this animal had some

(s) [Exostosis of the fang, produced by hypertrophy of the cement.]
(t) [Mr Tomes states that " although numerous instances may be
found where two teeth become united by cementum developed under
circumstances which constitute its formation a disease, yet in no well-
authenticated instance has the cementum become continuous with the
bone of the socket." (1) He believes in the existence of a law which
prohibits the union of the tooth to the jaw in Man. Anchylosis of the
teeth to the jaw is the normal condition in reptiles.]

(1) Tomes, op. cit., p. 445.