IMPROVE- MENTS IN ELECTRO-PLATING OR DEPOSITING METALS
Year: 1861

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Loughborough
Park, Brixton, in the County of Surrey, for the Invention of "IMPROVE-
MENTS IN ELECTRO-PLATING OR DEPOSITING METALS."-A communication
from abroad by Jabez Ellis Walcott, of Boston, Massachusetts, in the
United States of America.
PROVISIONAL SPECIFICATION left by the said George Tomlinson Bous-
field at the Office of the Commissioners of Patents, with his Petition,
on the 5th November 1861.
I, GEORGE TOMLINSON BOUSFIELD, of Loughborough Park, Brixton, in the
County of Surrey, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN ELECTRO-PLATING OR DEPOSITING METALS," to be as follows:-
Where sulphate of copper is employed for the purpose of electro-plating
with copper, if the metal (iron, for example) be soluble in sulphuric acid, it
will be corroded by the acid, and the copper will not adhere to it; but even
with metals that are not liable to be corroded by the acid the process is an
exceedingly slow one, and in consequence very expensive.
For the purpose of plating iron with copper, in order to secure the adhesion
of the two metals, and to prevent the corrosion of the iron, it has heretofore
been necessary to employ a solution composed of a mixture of cyanide of
copper and cyanide of potassa, but this process is without any practical utility

page_text: in the arts, firstly, on account of its great expense; secondly, on account of
the poisonous fumes which are given off whilst it is going on, and which are
very deleterious to the health of the operatives. A process, therefore, by
which copper may be deposited on and made to adhere to the surface of iron
and other metals, soluble in sulphuric acid, without the use of sulphate or
cyanide of copper, and which shall be less expensive than where either of
these substances are used, and also free from the poisonous effects before spoken
of, is a great desideratum in the arts. This desideratum is attained, and the
before-mentioned inconveniences, as well as the great expense heretofore
incurred are avoided by the improved process which I will now proceed
more particularly to describe.
A solution. of fused cyanide of potassa of great strength is employed in
connection with a powerful galvanic current; into the. cyanide of potassa
bath there are plunged, in the first place, two metal plates; the one of iron
and the other of copper, and the terminals of the battery are connected with
the plates. When the copper commences to be freely deposited on the iron
plate this plate is removed, and the article to be covered with copper sub-
stituted for it, being similarly connected with the battery terminal. In
this manner iron and other metals may be rapidly and economically plated
with
copper without the employment of either sulphate or cyanide of copper,
and without danger or inconvenience to the workmen. I am aware that a
weak solution of cyanide of potassa in water, in connection with a galvanic
current, has been employed for the purpose of plating with silver and some of
the other metals, but such process has proved entirely inapplicable and
unavailing for the purpose of plating iron with copper.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Tomlinson Bousfield in the Great Seal Patent Office
on the 3rd May 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
TOMLINSON BOUSFIELD, of Loughborough Park, Brixton, in the County of
Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of November, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said George Tomlinson Bousfield, Her special licence that I, the said George

page_text: Tomlinson Bousfield, my executors, administrators, and assigns, or such others
as I, the said George Tomlinson Bousfield, 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 Inven-
tion for "IMPROVEMENTS IN ELECTRO-PLATING OR DEPOSITING METALS," a commu-
nication to me from abroad by Jabez Ellis Walcott, of Boston, Massachusetts,
in the United States of America, upon the condition (amongst others) that I,
the said George Tomlinson Bousfield, 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 Létters Patent.
NOW KNOW YE, that I, the said George Tomlinson Bousfield, 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, reference being had to the Drawings
hereunto annexed, and to the letters and figures marked thereon (that is to
say) -
:-
The accompanying Drawings represent the apparatus which I employ in
carrying out the Invention. Where sulphate of copper is employed for the
purpose of electro-plating with copper, if the metal (iron, for example) be soluble-
in sulphuric acid, it will be corroded by the acid, and the copper will not..
adhere to it, but even with metals that are not liable to be corroded by the
acid the process is an exceedingly slow one, and in consequence very expensive.
For the purpose of plating iron with copper in order to secure. the adhesion-
of the two metals, and to prevent the corrosion of the iron, it has heretofore
been necessary to employ a solution composed of a mixture of cyanide of
copper and cyanide of potassa; but this process is without any practical utility
in the arts, firstly, on account of its great expense; secondly, on account of
the poisonous fumes which are given off while it is going on, and which are
very deleterious to the Health of the operatives. A process, therefore, by which
copper may be deposited upon and made to adhere to the surface of iron and
other metals soluble in sulphuric acid without the use of sulphate or of cyanide
of copper, and which shall be less expensive than where either of these sub-
stances are used, and also free from the poisonous effects before spoken of,
is, a great desideratum in the arts. This desideratum is attained, and the

page_text: before-mentioned inconveniences, as well as the great expense heretofore
incurred are avoided by the improved process, which I will now proceed more
particularly to describe.
I am aware that a weak solution of cyanide of potassa in water, in con-
nection with a galvanic current, has been employed for the purpose of plating
with silver and some of the other metals, but such process has proved entirely
inapplicable and unavailing for the purpose of plating iron with copper. In
the course of extensive experiments made by the Inventor, it has been discovered
that by the employment of a solution of fused cyanide of potassa of great
strength in connection with a powerful galvanic current,, he has been enabled
to plate iron and other metals rapidly and economically with copper, without
the employment of either sulphate or cyanide of copper, and without danger.
or inconvenience to the workmen.
To enable others skilled in the art to understand the improved process, I
will proceed to describe the manner in which it has been carried out.
A is a vessel of glass or of any other suitable material which will not suffer
decomposition when brought in contact with the agents employed, and will
permit the contained solution to be warmed. This vessel I partially fill with
a strong solution of cyanide of potassa, two pounds or thereabouts being
dissolved in one gallon of water, the temperature of the solution being raised s
to about 150 degrees Fahrenheit; into this bath I introduce the two poles of
a galvanic battery of sufficient strength to do the work. As this depends in a
measure on the size of the bath and of the articles to be plated, no definite
rule as to the strength of the current can be given for all cases; but a very
strong current being required, I use a Bunsen battery as represented in the a
Drawings, in which B is a glass vessel containing sulphuric acid and water;.
C, the zine to which is attached a copper wire b.
Within the zinc cylinder C
is placed the porous cup D, which is partially filled with nitric acid, and into
which is introduced a block E of carbon; to this block is connected another
copper wire f, to which is attached a large plate of copper 9 (the anode), and
to the wire b is attached the iron cathode h. The battery now being in
operation, the copper plate g and the iron plate h are both inserted into the
bath in the vessel A, when by the action of the galvanic current the copper of
the plate 9 is dissolved off. This action is permitted to go on until the
solution in the vessel A is sufficiently saturated with copper, which will be
indicated by a good deposit of copper on the iron plate h. The article to be
plated is now introduced into the bath A in contact with the pole 6 of the
battery, when the copper is deposited upon it, the supply of copper being kept
up in the bath by being dissolved off from the plate g. The operation may

page_text: thus be continued uninterruptedly until the article being operated upon has
been plated to the required thickness with copper.
The strength of the current required to commence the deposition of the
copper upon the iron will depend upon the amount of surface to be coated.
In general four Bunsen cups of one pint capacity are required to commence
the deposition of the copper upon a surface of one square foot of iron after the
iron is once coated with copper, and the deposition becomes one of copper
upon copper, it is simply necessary that the surface of zinc in the battery be
about equal to the surface on which the deposit is being made; were a less
powerful current employed at the commencement of the operation, the copper
which would be deposited would not adhere to the iron.
The important result which has been attained consists in the fact that the
copper deposited by the process adheres as firmly to the iron as in any of the
previously known processes, whilst the cost of the operation is so reduced,
and the operation is so divested of any deleterious effects upon the workmen,
that it can be made of practical value in the arts. This process may be
employed in depositing copper upon other substances than iron, but is par-
ticularly advantageous and economical in plating iron with copper.
Having now set forth the nature of this Invention, and explained the
manner of carrying the same into effect, I wish it to be understood that,
under the above recited Letters Patent, I claim the above described process
of electro-plating with copper, substantially as described.
In witness whereof, I, the said George Tomlinson Bousfield, have here-
unto set my hand and seal, this Twenty-third day of April, in the year
of our Lord One thousand eight hundred and sixty-two.
GEO. T. BOUSFIELD. (L.S.)