IMPROVE- MENTS IN THE APPLICATION OF THE ELECTROTYPE OR GALVANO-PLASTIC PROCESSES
Year: 1857

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
MENTS IN THE APPLICATION OF THE ELECTROTYPE OR GALVANO-PLASTIC
PROCESSES." A communication from Etienne Lenoir, of Paris, in the
Empire of France, Galvaniser.
Sealed the 30th June 1857, and dated the 9th January 1857.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on the
9th January 1857.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and 166, Buchanan Street, in the City of Glasgow, North Britain,
Gentleman, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE APPLICATION OF THE ELECTROTYPE OR GALVANO-PLASTIC PROCESSES," a
communication from Etienne Lenoir, of Paris, in the Empire of France,
Galvaniser, to be as follows:-
This Invention relates to certain improvements upon a mode or process for
producing entire statuetts or other objects by the electrotype process, for
which I obtained Provisional Protection on or about the Twenty-first day of
December, One thousand eight hundred and fifty-four, and consists in the

page_text: introduction into the interior of the moulds of a platinum or other metal wire,
which is used as an insoluble electrode, in place of the soluble anode employed
in the process described in the Provisional Specification herein-before re-
ferred to.
According to this Invention, after having moulded and metallised the object
to be produced, whether in plaster, gutta percha, gelatine, wax, or other
suitable plastic material capable of being formed into moulds, it is proposed to
introduce into the whole length of the cavity of the mould a skeleton or
frame of platinum wire insulated at each extremity. This frame is of the
same general contour as the article to be produced, and having been thus fixed
in the mould, is then placed in the bath in connection with the positive pole of
a galvanic battery. This platinum skeleton or frame serves as an insoluble
electrode, and decomposes the solution in the mould, causing the metal therein
to be deposited on the whole of the sides thereof, and allows of the free escape
of the gases evolved during the process.
It is proposed to use other metals than platinum as insoluble electrodes,
such as gold, silver, aluminium, &c., but preference is given to platinum, by
reason of its not being acted upon by the acid baths nor liable to oxidation.
In producing gold or silver articles, alkaline baths are used in place of the acid
baths employed for copper articles.
In the case of gold or silver deposits (when the mouth of the moulds is
sufficiently large) it is proposed to use with the insoluble platinum electrode a
piece of gold or silver fixed on to the platinum in the mouth of the mould,
thereby facilitating the deposition, by combining a soluble anode with an
insoluble electrode.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on the
4th July 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middle-
sex, and of 166, Buchanan Street, in the City of Glasgow, North Britain,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of January, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said John

page_text: Henry Johnson, Her special license that I, the said John Henry Johnson,
or such others as I, the said
my executors, administrators, and assigns,
John Henry Johnson, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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 "IMPROVE-
MENTS IN THE APPLICATION OF THE ELECTROTYPE OR GALVANO-PLASTIC PROCESSES,"
a communication from Etienne Lenoir, of Paris, in the Empire of France,
Galvaniser, upon the condition (amongst others) that I, the said John Henry
Johnson, by an instrument in writing under my hand and seal, should par-
ticularly 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 John Henry Johnson, 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: -
The said Invention relates to certain improvements upon a mode or process
for producing statuettes or other similar objects in relief by the electrotype
process, for which process I obtained Provisional Protection on or about the
Twenty-first of December, One thousand eight hundred and fifty-four.
After having made a mould either in plaster, gutta percha, or other suitable
material, and after having coated the inside of that mould with metal, it was
proposed to cut out of a sheet of copper or other soluble metal a silhonette or
contour plate, representing the sectional outline of the object to be produced,
and this plate was suspended inside the mould, care being taken to insulate it
from the deposit of metal intended to be formed on the interior of the mould.
This sectional outline plate, which served as a soluble anode, was put into
communication with the positive pole of a battery, which dissolved the meta!
of the plate and precipitated it upon the internal surface of the mould.
The process above described was attended with several difficulties. Some-
times oxidation of the forming the sectional outline plate ensued, whereby the
work was interrupted, and in the case of very small moulds it was not easy to
introduce the plate.
The new process, however, herein-after described, and which forms the
subject of the present Invention, entirely obviates these inconveniences.
According to this Invention, after having made a mould of the object to be

page_text: produced (such mould' being composed either of gutta percha, gelatine, bees'-
wax, or other suitable material), and having coated the interior with metal, I
introduce into the interior of the mould a shell or skeleton made of platinum
in the shape of wire, plate, strips, or in some other convenient form, the two
extremities of which are insulated by gutta percha, glass, or other non-con-
ducting material. This platinum shell represents, when inside the mould, the.
external form of the object that is to be reproduced, and when thus fixed,
the whole is immersed in the bath, which is in connection with the positive
pole of the battery. The platinum thus arranged fulfils the office of an
insoluble electrode; it decomposes the liquid inside the mould, and precipitates
the copper upon its sides, allowing the resulting gases to escape through the
liquid.
The platinum when in the shape of wire can be introduced into very intri-
cate and delicate moulds in consequence of its extreme fineness, an advantage
which cannot be obtained by the use of a metallic outline plate, employed in
the manner herein-before referred to.
By the employment in place of platinum and other metals (such as gold;
silver, aluminum, copper, tin, or lead), similar effects may be obtained, taking
care to employ them as insoluble electrodes, and applying them in the same
manner as the platinum. I prefer, however, to employ platinum, as the
best results have been obtained from it, and as it is not injured by the acids
that are used, nor is it liable to oxidation.
For the production of ornamental objects of gold or silver I employ the
same process, the only variation being that in that case the baths are alkaline,
whereas when a copper precipitate is required I make use of an acid bath.
When gold or silver deposits are required, and when the opening of the
moulds is large, I can employ in combination with the platinum a small piece
of gold or silver to form a soluble anode, and this I attach to the platinum at
the opening of the mould. This considerably facilitates the metallic deposit,
since I thus obtain a soluble anode as well as an insoluble electrode.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion.
to describe or refer to, as certain variations may be made therefrom without
deviating from the principles or main features of the said Invention; but what
I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is, the
application and use to and in the electrotype process of a shell or skeleton

page_text: made of platinum or other metal and introduced into the mould as an
insoluble electrode, in lieu of the soluble anode described in my Provisional
Specification herein-before referred to.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my
hand and seal, this Fourth day of July, One thousand eight hundred
and fifty-seven.
J. HENRY JOHNSON. (L.S.)