IM- PROVEMENTS IN MOUNTING OF FITTING ARTIFICIAL TEETH
Year: 1862

page_text: LETTERS PATENT to James Thom, of Canterbury Place, Lambeth, in
the County of Surrey, Mechanical Dentist, for the Invention of "IM-
PROVEMENTS IN MOUNTING OF FITTING ARTIFICIAL TEETH."
Sealed the 13th February 1868, and dated the 12th September 1862.
PROVISIONAL SPECIFICATION left by the said James Thom at the
Office of the Commissioners of Patents, with his Petition, on the
12th September 1862.
I, JAMES THOM, of Canterbury Place, Lambeth, in the County of Surrey,
Mechanical Dentist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MOUNTING OR FITTING ARTIFICIAL TEETH," to be as follows:-
A model of the mouth having been taken in wax (or other plastic material)
and the teeth placed in their proper positions, a mould is taken therefrom in
plaster of Paris in the usual manner. The wax being removed from the
mould, its place is supplied with indian-rubber and sulphur, which is heated
to a temperature of about 350 degrees of Farenheit, when the indian-rubber
becomes partially melted, and takes the form of the mould, it at the same time
becomes vulcanised, and hardens in cooling. It also shrinks, it is therefore
taken out, trimmed, and replaced in the mould, and heated to about 220° in
a screw press, which forces the indian-rubber into close and perfect contact
with the surfaces of the mould, in which state it is cooled, when it permanently
and accurately retains the exact form of the mould.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Thom in the Great Seal Patent Office on the
12th March 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
Tпом, of Canterbury Place, Lambeth, in the County of Surrey, Mechanical
Dentist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of September, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James Thom, Her special licence that I, the said James Thom,
my executors, administrators, and assigns, or such others as I, the said James
Thom, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend within the United Kingdom of Great Britain and Ireland, the
Channel Islands and Isle of Man, an Invention for "IMPROVEMENTS IN
MOUNTING OR FITTING ARTIFICIAL TEETH," upon the condition (amongst others)
that I, the said James Thom, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Thom, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
A model of the mouth to which the teeth are to be fitted having been taken
in wax (or other plastic material) and the artificial teeth placed in their
proper positions, a cast is taken therefrom in plaster of Paris in the usual
manner. After this mould has been completed and become hard the wax is
removed, and its place supplied with a mixture of indian-rubber and sulphur,
which is heated to a temeprature of about 330 degrees of Fahrenheit's
thermometer, when the indian-rubber becomes semi-fluid, and takes the form
of the mould, at the same time it becomes vulcanized and hardened. In
cooling the vulcanized indian-rubber is found to shrink, or become distorted
from the original pattern, and, therefore, does not accurately fit the mouth

page_text: from which the model was taken. In order to remedy this defect, and give
the required accuracy to the artificial gum, I submit it to the following
additional and corrective process, which I claim as contituting my said Inven-
tion. Having trimmed the vulcanized indian-rubber and made any necessary
corrections thereto, I replace it (the teeth being imbedded in their
proper
positions) in the plaster mould, within a metal collar of a conical shape,
which, by means of a screw press brings the parts of the plaster mould into
close contact with each other, and with the vulcanized indian-rubber. While
subjected to this pressure I heat it to about 220 degrees of Fahrenheit, which
so far softens the vulcanized indian-rubber as to cause it to conform itself
strictly to the mould. In this state it is left to cool and harden; on being
taken out it retains the true form of the mould, and accurately fits the mouth
from which the original model was taken. Although I have described this
process as being applied to. vulcanized indian-rubber, it is also equally
applicable to any other vulcanized vegetable gum.
In witness whereof, I, the said James Thom, have hereunto set my
hand and seal, this Twelfth day of March, in the year of our Lord
One thousand eight hundred and sixty-three.