Page 274 - My FlipBook

246 THE MICRO-ORGANISMS OF THE HUMAN MOUTH. ;
has been using the sulphate of copper in this manner for some
time, without any discoloration resulting.
Various substances suggest themselves, which, being incor-
porated with cement or gutta-percha, might do good service as
antiseptic dressings over diseased pulps or over softened dentine
first of all, naturally, the bichloride of mercury. Which of the
many available antiseptics, however, is best adapted to the pur-
pose must be determined b}' further experiments in the labora-
tory and in practice.
The practice of treating exposed pulps, whether healthy or
diseased, to a bath of concentrated carbolic acid has been sharply
criticised by various writers. There are nevertheless many
practitioners in high standing who treat all exposures of the
pulp in this manner, and claim to obtain better results than by
any other method. I will not venture to say that this may not
be so, because the ill eifects of so severely cauterizing the pulp-
tissue may be balanced by the good effects of thorough antiseptic
treatment. If we, hoAvever, could attain the same object by the
use of less irritating agents, our probability of success would be
much greater.
Further experiments relating to this subject are now in pro-
gress, and will be reported in due time.

THE ACTION OF TOBACCO UPON THE TEETH.
Five grammes of old Virginia plug were boiled fifteen minutes
in 50 e.cm. of water, the loss by evaporation being constantly
replaced ; the decoction was then filtered, and a portion added
to an equal volume of saliva with sugar. This produced a mix-
ture scarcely stronger than that which many veteran chewers
carry around in their mouths all day, and in it the bacteria led
only a miserable existence.
IVIuch more remarkable, however, was the action of tobacco-
smoke upon the micro-organisms of the mouth; the smoke from
the' first third or last quarter of a Colorado C^laro cigar being
found amply sufiBcient to sterilize 10 c.cm. of a beef-extract-
sugar solution, previously richly infected with l)acteria from de-
cayed dentine.