Periscope of Medical and General Science in their Relations to Dentistry. [Volume: 2, Issue: 5, December, 1860, pp. 289-304]

298

THE DENTAL COSMOS.

connection of these nervous cellules with the central parts of the nervous
system.
"V. If the anatomical difference disappears in the peripheral capillary
nervous net-work from the fact that the axis cylinders are confounded
together, it is not the same with the physiological difference which always
exists, (the same as we see in the capillary blood-vessels,) and it is probable that its activity may be carried along (traduise) by determinate
directions of the courant of nervous force with the substance of the nerve
(avec la matiere.)"
"Sowething new about Gold.-At a late meeting of the Manchester
(England) Geological Society, an interesting paper was read by T. A.
Readwin, Esq., on gold discoveries which had been made by him in
Merionethshire, Wales, and he exhibited numerous rich specimens of ore
taken from it. He stated that Sir R. Murchison had laid it down that
'the most usual position of gold is in veinstones that traverse altered
paleozoic slates frequently near their junction with eruptive rocks,
whether of igneous or aqueous origin.' This statement was remarkably
corroborated by the position of the quartzose vein in Wales, which traversed altered paleozoic slates near the junction of an eruptive bar of
porphyritic greenstone. The same law was found to hold good in all the
gold-bearing quartzoze veins of Wales. Several shoots and bunches of
gold were found in one mine. In one instance, 100 poundsof goldstone
yielded 14- ounces of fine gold. Lately, operations were commenced to
mine the quartz upon what is called 'St. David's lode.' Of the rock
which had been raised and broken, many stones were found very rich in
gold and sulphides of copper, and there was another mineral which had
been termed white metal, that had been examined by several mineralogists,
none of whom knew what it was, an ignorance which was shared in by
the members of the association after much examination. Cubes of this
white metal were found in cubes of gold, and vice versa; and wherever
it was found, it was a sure indication that gold was there also.
"Mr. Readwin, in his paper, asserted that at a certain temperature
gold would volatilize and escape mechanically, though such was not the
general belief. Mr. Atkinson, a member, stated that gold was sublimated
from the earth by internal heat."-(Sci. Amer.)
1Ranula.-In one of a series of interesting papers on "Anatomy in its
Relations with Medicine and Surgery," published in the Medical and
Surgical Reporter, DR. D. HAYES AGNEW makes the following remarks
on this subject: "A tumor is met with beneath the end of the tongue,
rising from the floor of the mouth, to which the name ranula has been
applied. It involves the ducts of the sub-lingual glands, the excretory
orifices of which here open. These become obstructed by some substance,
either mechanical or inflammatory, the secretion accumulates behind, distending them finally into a semi-transparent tumor. Sometimes they are
found to be firm and resisting in the texture. In such cases the distention has provoked an inflammatory exudation and its organization into
fibrous tissue. The transparency will depend upon the attenuation of the
mucous membrane. This same morbid condition may be present in a
very limited degree, confined even to a single duct, so as to resemble a
little vesicle. The cure of such can rarely be accomplished by puncture
and evacuation of the contents; the wound you make will soon heal, and
as the duct or ducts are not restored to a previous condition, the swelling