American Dental Convention. [Volume: 2, Issue: 2, September, 1860, pp. 100-121]

106

THE DENTAL COSMOS.

water of the other division add as much sulphate of copper (blue vitriol)
as it will hold in solution, i.e. a quarter of a pound to the quart. Now,
having your vessel, liquids, and impression ready, take a piece of stout
copper wire and bend it for a conductor, so that it may hang over the partition and extend down into the liquids on either side. To one end of this
conductor attach a plate of zinc to be inserted in the acid, and to the other
end affix the impression so that the copper wire will come in immediate
contact with some portion of the surface coated by the plumbago, bronze,
or whatever metallic surface may have been rubbed over the impression.
By hanging this conductor across the partition, with the end to which
the zinc is attached immersed in the acid, and the impression in the opposite side containing the solution of copper, you will have a most capital
galvanic battery, the action of which will separate and precipitate the
copper contained in the solution and cause it to form a beautiful copper
surface on the face of the impression. In the course of ten or twelve
hours this coating of copper will be of sufficient thickness to form the face
of a perfect model in pure metallic copper, and an exact fac-simile of
the mouth from the impression, forming a disk of copper in which can be
poured or run fusible metal, britannia, or any of the metals used as models
for dental purposes, giving it the requisite thickness, shape, etc., for
swagging or hammering when used with the counter model or female cast.
"I have found this an excellent method for obtaining a most correct and
perfect model of such impressions as are very uneven, having undercut or
projecting alveolar ridges where it is almost impossible to obtain a correct
metallic model by the ordinary process."
Dr. A. Westcott referred to a style of forceps which he invented
many years ago, and took the trouble to travel to the City of Washington to present to the notice of his friend Dr. Maynard, of that city.
Upon examination, he said he considered them a valuable inventionbut, to the surprise of Dr. Westcott, opened his case and produced a
similar pair; he said, however, that it did not detract from the originality,
as the invention was original with both. He would say, that he had used
a method for obtaining metallic dies similar to the one proposed by Dr.
Burras, many years ago.
Dr. Burras remarked, he had stated his mode of practice to many of the
most prominent mechanical dentists in this country, all of whom said it
was a new thing; and he thought Dr. Westcott should at least be
censured for retaining so valuable a secret so many years.
Dr. Wm. B. Roberts spoke of the objection to the use of a copper face
die, it being as soft as lead.
Dr. Westcott stated that he had not used that method in practice, the
process of electrotyping being so exceedingly slow, taking twenty-four
hours to get a thin copper plate.
Dr. Burras remarked, the copper precipitated is perfectly pure, and
though electrotyping is nothing new, yet the patentee of the copper-faced
type has accumulated an independent fortune. That, however, is precipitated upon a metallic type, while his is made upon the plaster impression.