Page 36 - My FlipBook

16 Natural History of the Teeth. —
teeth have often been found in a very perfect state of preserva-
tion, while all the other bones have crumbled into dust. A
tooth is composed of two substances ; the bony part, and the
enamel ; the former is organized and possessed of vitality,
vascularity and sensibility; the latter is crystalline.
The following is the analysis of the human teeth, by the
Swedish chemist Berzelius, and is more elaborate than that of
any other chemist.
The enamel of the adult teeth contains in 100 parts :
Phosphate of lime 85.3
Fluate of lime 3.2
Carbonate of lime 8.
Phosphate of magnesia - - - - 1.5
Soda and muriate of soda - - - 1.
Animal matter and water - - - 1.
100.
The bone of the adult teeth according to the same celebrated
chemist, contains in 100 parts —
:
Phosphate of lime - - - - - 62.
Fluate of lime 2.
Carbonate of lime ----- 5.5
Phosphate of magnesia - - - - 1.
Soda murate of soda - - - - 1.5
Gelatine and water ----- 28.
100.
A tooth is anatomically divided into the crown, neck and
fang. The crown is covered by the enamel, which is very
thick on their cutting and grinding surfaces, and gradually
grows thinner towards the neck, where it almost insensibly
terminates. The teeth are articulated with the jaw-bone* in
* "It is curious to observe how differently the teeth are situated in
different animals. In the more perfect, they are placed in sockets in the
jaw-bones, some of which are in many kinds rendered moveable, as the