IMPROVEMENTS IN THE PREPARATION OF NON-CONDUCTING SUBSTANCES FOR THE DEPOSITION THEREON OP METALS BY ELECTRIC ACTION
Year: 1861

page_text: LETTERS PATENT to Bernard Piffard, of 17, Caroline Villas, Kentish
Town, in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN THE PREPARATION OF NON-CONDUCTING SUBSTANCES FOR
THE DEPOSITION THEREON OP METALS BY ELECTRIC ACTION."
Sealed the 16th April 1861, and dated the 19th January 1861.
PROVISIONAL SPECIFICATION left by the said Bernard Piffard at the
Office of the Commissioners of Patents, with his Petition, on the 19th
January 1861.
I, BERNARD PIFFARD, of 17, Caroline Villas, Kentish Town, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE PREPARATION OF NON-CONDUCTING SUBSTANCES FOR THE
DEPOSITION THEREON OF METALS BY ELECTRIC ACTION," to be as follows:-
The surface to which it is desired to impart a metallic coating is washed
with a solution of nitrate of silver in such a manner that a film of the solu-
tion adheres to the whole of the surface, which is then thoroughly dried, and
afterwards exposed to the action of sulphuretted hydrogen gas. The result of
this process is that a conducting surface of metallic silver will be produced.
which can then be treated by any of the known methods of obtaining the
electro-deposition of metals. If the surface will not retain a complete film

page_text: of the solution of nitrate of silver, it should be previously washed with a thin
solution of gum or other suitable substance, and then dried before applying the
solution of nitrate of silver.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Bernard Piffard in the Great Seal Patent Office on the 16th
July 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BERNARD
PIFFARD, of 17, Caroline Villas, Kentish Town, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of January, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Bernard Piffard, Her special licence that I, the said Bernard Piffard, my
executors, administrators, and assigns, or such others as I, the said Bernard
Piffard, 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 THE
PREPARATION OF NON-CONDUCTING SUBSTANCES FOR THE DEPOSITION THEREON OF
METALS BY ELECTRIC ACTION," upon the condition (amongst others) that I, the
said Bernard Piffard, my executors or administrators, by an instrument 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 immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said Bernard Piffard, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:—
The surface to which it is desired to impart a metallic coating is washed
with a solution of nitrate of silver in such a manner that a film of the solution
adheres to the whole of the surface, which is then thoroughly dried, and

page_text: afterwards exposed to the action of sulphuretted hydrogen gas.. The result
of this process is, that a conducting surface of metallic silver will be produced,
which can then be treated by any of the known methods of obtaining the
electro-deposition of metals. If the surface under treatment will not retain a
complete film of the solution of nitrate of silver, it should be previously washed
with a thin solution of gum or other suitable substance, and then dried before
applying the solution of nitrate of silver.
Having thus stated the nature of my Invention, I will proceed more fully
to describe the manner of performing the same.
The non-conducting surface is to be first coated all over with a saturated
solution of nitrate of silver, taking care that the solution adheres to all parts
of the surface which it is desired should be made conducting. The surfaces
thus coated are then to be dried, and they are then to bo' subjected to the
action of sulphuretted bydrogen gas till the silver is rendered metallic, which I
believe may be most conveniently done by streams or jets of such gas against
the coated surfaces. In those cases where the non-conducting surfaces are
greasy or wanting in cleanliness, they should be well cleansed before applying
the solution of nitrate of silver, in order to insure that the solution will adhere
all over the surface. When gutta percha is the non-conducting surface, I have
found it advantageous to wash the surface quickly with oil of turpentine, and
to dry it, and then to apply the coating of the solution of nitrate of silver. In
those cases where the solution of nitrate of silver will readily adhere, no
preparation of the surface is required.
Surfaces thus rendered conducting are then suitable for having metals
deposited thereon by electric currents, as is well understood.
In witness whereof, I, the said Bernard Piffard, have hereunto set my
band and seal, this Eighth day of July, in the year of our Lord One
thousand eight hundred and sixty-one.
BERNARD PIFFARD. (L.S.)