IMPROVEMENTS IN COATING IRON AND CERTAIN OTHER METALS AND ALLOYS OF METALS
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, THOMAS
HENRY RUSSELL, of Wednesbury, Patent Tube Manufacturer, and JOHN
STEPHEN WOOLRICH, of Birmingham, Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent, under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Nineteenth day of
March, One thousand eight hundred and forty-nine, in the twelfth year of Her
reign; did, for Herself, Her heirs and successors, give and grant unto us, the
said Thomas Henry Russell and John Stephen Woolrich, our exors, adiñors,
and assigns, Her especial licence, full power, sole privilege and authority, that
we, the said Thomas Henry Russell and John Stephen Woolrich, our exors,
adñmors, and assigns, and such others as we, the said Thomas Henry Russell
and John Stephen Woolrich, our exors, adñors, or assigns, should at any time
agree with, and no others, from time to time and at all times during the term
of years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, our
Invention of "IMPROVEMENTS IN COATING IRON AND CERTAIN OTHER METALS AND
ALLOYS OF METALS;" in which said Letters Patent is contained a proviso, that
we, the said Thomas Henry Russell and John Stephen Woolrich, or one of us,
should cause a particular description of the nature of our said Invention, and
in what manner the same is to be performed, by an instrument in writing
under our hands and seals, or under the hand and seal of one of us, to be
inrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being therounto had, will more fully
and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, we, the said
Thomas Henry Russell and John Stephen Woolrich, do hereby declare that
the nature of our said Invention, and in what manner the same is to be per-
formed, are fully described and ascertained in and by the following statement
thereof, that is to say:-
Our Invention consists of two parts; and we note that we mean by electricity
any electrical current which can or may be used for the purpose of depositing
metals, whether it is obtained from the galvanic battery, magnets, electrical
machine, or any other source, and that we mean by certain other metals and
alloys of metals those metals and their alloys which may be used for the
purpose of manufacture, the chief being lead, tin, bismuth, copper, antimony,
nickel, zinc. The degrees of heat spoken of in this Specification are those
marked upon Fahrenheit's thermometer, the one usually employed in Great
Britain and Ireland.
The first part of our Invention consists of the application of cadmium and
its alloys for coating the surfaces of iron and certain other metals and alloys of
metals, either. for the purpose of. affording protection from decay. or as a
superior coating, and we can apply this metallic coating. in several ways, one
being by means of electric deposition, in the manner-well known and practised
when depositing other metals. The-mode we prefer for depositing this metal
is to take cadmium and dissolve it in nitric acid of commerce diluted withi
about six times its bulk of water, and which water we prefer to be warm, about
eighty degrees or one hundred degrees, adding the diluted acid- by degrees-till
the cadmium is dissolved. To this solution of cadmium we add a solution of
carbonate of soda (which is made by dissolving one pound of the ordinary
crystals in one gallon of water), until the cadmium is precipitated, and the
precipitate thus obtained is to be washed four or five times with tepid water.
The precipitate is now. fit for use, and various solvents for this- compound'
(which we believe to be the most convenient one) of cadmium may be em-
ployed, but cyanide of potassium is preferred. We add as much of a solution.
of cyanide of potassium in water. as will dissolve the precipitate of cadmium,
and then add about one tenth more of the solution of cyanide of potassium, so
that it shall be in excess. The strength of this solution of cadmium may vary,
but a solution containing six, ounces (troy) of the metal to the gallon, which is
the solution we believe to be the best. The solution is now fit for use, and
we prefer to keep it warm while being used, about eighty degrees or one
hundred and twenty degrees. The vessels we employ are made by covering
the outside of a strong wooden vat with sheet lead, in the manner the vats are
made for holding solutions of silver for electro-platers, and in working we

page_text: usually cause a plate of cadmium to be so placed in this vessel as to surround
at the distance of a few inches the articles upon which it is wished to have a
coating of cadmium. Should a galvanic battery be the source of the electric
current, the wire from the zinc end is to be in contact with the goods to be
coated, and the other wire with the plate of cadmium. The metal to be coated
is first to be well cleaned, as heretofore practised when intended to be coated
with other metal. The plate of cadmium will generally require to be occa-
sionally cleansed from any scurf which may get upon it, and which might
otherwise interfere with the progress of the working. Cadmium may be used
in solution with other metals, and be precipitated in combination, in which
cases we either use plates of the alloy it is desired to have precipitated, or wo
use plates of the separate metals in connection, the solution being from
time to time stirred. In depositing alloys of cadmium, we recommend that
the cyanide of potassium should not be in any great excess, and generally we
find that in such cases somewhat more power of electricity is desired than
when using cadmium only; and in this case when we find in working either
metal in excess, we substitute a plate of the metal which is deficient in the
solution for the one which is in excess in the solution.
Another part of our Invention consists of coating metals with cadmium' and
its alloys, and consists of dipping the metals into a melted bath of the coating
metal. For this purpose we prefer to alloy the cadmium with tin and zinc,
and the mode of operating we prefer is as follows:-The alloy of cadmium is
melted in a suitable iron vessel, set in brickwork, having a fire underneath;
and the melted alloy should be covered with a layer of melted fat, to prevent
contact of air. The cleaned metal to be coated is first dipped into a saturated
solution of chloride of zinc, and then put into the melted metal and well
stirred about until it is coated; it is then taken out, and, while warm, cleaned
with sawdust, or by any any other convenient method, from any fatty matter
which may adhere to it. When we alloy with tin, we prefer four hundred
parts of cadmium and two hundred parts of tin; when with zinc, four hundred
parts of cadmium and one hundred and fifty of zine; we give preference to
this mode of applying cadmium and its alloys, which melt at about the same
heat as cadmium. We have found that cadmium may be applied alone in
this manner with copper and its alloys, but generally we believe it desirable
when used in a melted state that it should be alloyed.
Another part of our Invention consists of applying cadmium or its alloys as
a means of preserving iron and other metals, by applying such metal in contact,
by mechanical or other means, in like manner to what zinc has heretofore been
applied; thus is part of an iron screw-propeller or paddle-wheel to be coated

page_text: with cadmium, the iron structure will be presented, whilst the cadmium
oxidizing slowly will last better than zinc.
Another part of our Invention consists in a peculiar mode of depositing
copper in alloy with other metals; for which purpose we take ten pounds of
acetate of copper, one pound of acetate of zinc, ten pounds of acetate of potash,
five pounds of benzoate of potash, and dissolve these in five gallons of hot
water; then add as much cyanide of potassium in solution as will dissolve the
precipitate, which is caused on adding it; and then about one tenth more
cyanide of potassium, so that it may be in excess. The process of working is
the same as that described under the first part of our Invention, the plate of
metal in the solution having the same constitution as the deposited alloy or two
sheets of metal, one copper and the other zinc, connected together; and in this
case, when we find either the copper or the zinc in working to become in ex-
cess, we substitute a plate of the metal which is deficient in the solution for the
one which is in excess in the solution, restoring the plate as soon as the desired
condition is again obtained, removing at the same time the substituted plate.
Other metals may be alloyed with copper, and the mode of proceeding is like
that above described. We would remark that we are aware that other
solutions have been proposed for depositing alloys of copper. The novelty of
this part of our Invention consists of the solutions containing the soluble
acetates and benzoates with cyanide of potassium.
Having thus described the nature of our Invention, we would have it under-
stood that we do not confine ourselves to the particulars and details herein
described, so long as the peculiar character of any part of our Invention
be retained; but what we claim is,―
First, the coating of metals and alloys of metals with cadmium and alloy's
thereof, and also the preserving iron and other metals by partially coating or
applying cadmium or its alloys in contact therewith, as described.
And, secondly, we claim the mode of coating metals and alloys of metals
with alloys of copper by employing soluble acetates and benzoates with cyanide
of potassium.
In witness whereof, we, the said Thomas Henry Russell and John
Stephen Woolrich, have hereunto set our hands and seals, this
Eleventh day of September, in the year of our Lord One thousand
eight hundred and forty-nine.
THOMAS HENRY (L.s.) RUSSELL.
JOHN STEPHEN
(L.S.) WOOLRICH.

page_text: AND BE IT REMEMBERED, that on the Eleventh day of September, in
the year of our Lord 1849, the aforesaid Thomas Henry Russell and John
Stephen Woolrich came before our said Lady the Queen in Her Chancery,
and acknowledged the Specification aforesaid, and all and every thing therein
contained and specified, in form above written. And also the Specification
aforesaid was stamped according to the tenor of the Statute made for that
purpose.
Enrolled the Nineteenth day of September, in the year of our Lord One