determined to try whether it would act on enamel and dentine, but did
not expect that it would succeed with so hard a substance as enamel.
Dr. Klein gave me some thin transverse slices of the canine tooth of a
dog; small angular fragments of which were placed on four leaves; and
these were examined each succeeding day at the same hour. The results
are, I think, worth giving in detail.] [page 107]
[Experiment 1. May 1st, fragment placed on leaf; 3rd, tentacles but
little inflected, so a little saliva was added; 6th, as the tentacles
were not strongly inflected, the fragment was transferred to another
leaf, which acted at first slowly, but by the 9th closely embraced it.
On the 11th this second leaf began to re-expand; the fragment was
manifestly softened, and Dr. Klein reports, a great deal of enamel and
the greater part of the dentine decalcified.
Experiment 2. May 1st, fragment placed on leaf; 2nd, tentacles fairly
well inflected, with much secretion on the disc, and remained so until
the 7th, when the leaf re-expanded. The fragment was now transferred to
a fresh leaf, which next day (8th) was inflected in the strongest
manner, and thus remained until the 11th, when it re-expanded. Dr.
Klein reports, a great deal of enamel and the greater part of the
dentine decalcified.
Experiment 3. May 1st, fragment moistened with saliva and placed on a
leaf, which remained well inflected until 5th, when it re-expanded. The
enamel was not at all, and the dentine only slightly, softened. The
fragment was now transferred to a fresh leaf, which next morning (6th)
was strongly inflected, and remained so until the 11th. The enamel and
dentine both now somewhat softened; and Dr. Klein reports, less than
half the enamel, but the greater part of the dentine decalcified.
Experiment 4. May 1st, a minute and thin bit of dentine, moistened with
saliva, was placed on a leaf, which was soon inflected, and re-expanded
on the 5th. The dentine had become as flexible as thin paper. It was
then transferred to a fresh leaf, which next morning (6th) was strongly
inflected, and reopened on the 10th. The decalcified dentine was now so
tender that it was torn into shreds merely by the force of the
re-expanding tentacles.]
From these experiments it appears that enamel is attacked by the
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