THE VITRIFICATION OF GELATINOUS IMPRESSIONS OBTAINED EITHER BY PHOTOGRAPHY OR FROM COPPER OR STEEL PLATES
Year: 1879

page_text: LETTERS PATENT to Emile Salvy, Chemist, of No. 1, Rue Laffitte, Paris, for
the Invention of "THE VITRIFICATION OF GELATINOUS IMPRESSIONS OBTAINED
EITHER BY PHOTOGRAPHY OR FROM COPPER OR STEEL PLATES."
Sealed the oth T... 1070
PROVISIONAL SPECIFICATION left by the said Emile Salvy at the Office
of the Commissioners of Patents on the 24th January 1879.
EMILE SALVY, Chemist, of No. 1, Rue Laffitte, Paris. "THE VITRIFICATION OF
GELATINOUS IMPRESSIONS OBTAINED EITHER BY PHOTOGRAPHY OR FROM COPPER
OR STEEL PLATES."
According to this improved process vitrifiable oxides are used for the coloring of
the gelatine, and after treating the material with such it is plunged into a solution
which modifies its nature in such manner that the oxide can be vitrified without
causing any swelling, blistering, and tearing, as is usual if the material has not
undergone this particular preparation.
When this process is used for preparing gelatinous prints, these latter if obtained
by photographic processes may be produced either on paper, from which they can
be transferred, or they may be directly produced on glass; the same methods can be
employed in printing from copper or steel plates.
This process can be used not only for glass but also for the ornamentation of
crystal, glass, porcelain, stone-ware, and enamel.
BLETHOD OF OPERATION.
I will describe here the improved process as employed to obtain and prepare
gelatinous impressions although it is evident that it may be used for treating and
preparing for vitrification gelatine in any other shape or for any other desired
purpose.
I dissolve in a water bath 10 grammes of gelatine in 100 grammes of water, and
then color this liquid by means of a metallic oxide to which I add a quantity of

page_text: flux. This mixture can be poured in a thick layer on unsized paper, and then after
it is dried made sensible to the action of the light by means of a bath of bichromate,
and finally treated in the manner of what is commonly called crayon-prints; or it
may be poured in a mould or over an engraved plate, and by a special press affixed
directly to glass or simply to paper, from which it can be transferred.
Whatever methods inay be employed for this first operation the gelatinous print,
whether it be direct or transferred, after it is perfectly dried is for a quarter of an
hour dipped into a solution of 4 parts by weight of permanganate of potash in 100
parts of water, or into a solution in water of any other substance which has the
properties of making gelatine insoluble mixed with nitrate of potash. I will mention
only a few of such substances, as sulphate of alumina, tan, gallic acid, &c., but do
not confine myself to these as there are many other chemicals which make gelatino
insoluble and which can be employed with the same satisfactory results when mixed
with nitrate of potash.
After being immersed for a quarter of an hour in one of these baths the print is
carefully washed in clear water and then left to dry spontaneously. Finally it is
covered with a thin layer of flux, and in this stato it is ready to be subjected to
the heat of a suitable oven.

page_text: 4tb. The application of this process to gelatinous impressions whether they bo
produced by a photographic process or printed from copper or steel plates.
In witness whereof, I, the said Emile Salvy, have hereunto set my hand
and seal, this Twenty first day of July, in the year of our Lord Ono thou-
sand eight hundred and seventy nine.