Page 78 - My FlipBook

have been hitherto unaccountably overlooked. By the wri-
tings of those great men we are informed, that a certain num-
ber of the permanent teeth begin to be formed previous to
birth, but we are still perfectly ignorant respecting the man-
ner of their formation or connexion ; and have nothing to
guide us but imaginary conjectures, respecting the teeth
which appear at a more advanced period of life. I think it
unnecessary to say any thing on the hypothetical supposi-
tions of Hippocrates, Fallopius, Eustachius, &c. but will
dwell on the facts which I have discovered, and which I
mentioned to a few celebrated anatomists, five years since in
London.
When the rudiments of the temporary teeth are tolerably
advanced, the internal part of the gum, or rather the upper
part of each membrane destined to form one of the tempo-
rary teeth, sends off a new sac. These sacs, situated as
just now described, are each at first contained in the socket
of the one to which it is to succeed ; and are so intimately
connected with the membranes of the temporary teeth, that
they cannot be separated without tearing one or both, and
may be torn along with the first sacs out of the sockets.
This circumstance might have misled Dr. Nesbitt, but it is
strange he did not observe the commencement of the perma-
nent sockets, which are very evident in every subject I ex-
amined, just before or at birth. These sacs were observed
by the ingenious Mr. Hunter, for he says,* " There is ano-
ther pulpy substance opposite to that which we have de-
scribed it adheres to the inside of the capsula, where the
;
gum is joined to it, and its opposite surface lies in contact
with the basis of the above described pulp, and afterwards

Nat. Hist, pages 94 and 95.