IMPROVEMENTS IN THE METHOD OR MEANS OF DEPOSITING NICKEL UPON METALS, AND IN THE PREPARATION OF THE ARTICLES TO BE COATED FOR THE RECEPTION OF THE NICKEL COATING
Year: 1871

page_text: LETTERS PATENT to John Unwin, of Sheffield, in the County of York,
Manufacturer, for the Invention of "IMPROVEMENTS IN THE METHOD
OR MEANS OF DEPOSITING NICKEL UPON METALS, AND IN THE PREPARATION OF
THE ARTICLES TO BE COATED FOR THE RECEPTION OF THE NICKEL COATING."
Sealed the 14th June 1872, and dated the 21st December 1871.
PROVISIONAL SPECIFICATION left by the said John Unwin at the
Office of the Commissioners of Patents, with his Petition, on the
21st December 1871.
I, JOHN UNWIN, of Sheffield, in the County of York, Manufacturer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE METHOD OR MEANS OF DEPOSITING NICKEL UPON METALS, AND IN THE
PREPARATION OF THE ARTICLES TO BE COATED FOR THE RECEPTION OF THE NICKEL
COATING," to be as follows:-
My Invention has for its object the depositing upon all kinds of
metal, or coating metals with pure nickel in an improved and more
efficient manner than heretofore.

page_text: My improvements consist in the employment of a solution prepared
in an improved and different manner from any solution hitherto used
for the deposition of nickel, in the mode of preparing the articles to be
coated for the reception of such coating of nickel, and in the method
by which the solution is kept in good working order for any length of
time.
In carrying out my Invention, I make the solution from the following
substances, in or about the following proportions, viz:-I take, say
three parts of nitric acid, two of sulphuric acid, one of water, and one
of nickel. The nickel is dissolved in the acids and allowed to stand
twenty-four hours, when an ammoniacal salt is added thereto; the
resulting product is then dissolved in water, and the solution is ready for
use. The articles upon which the nickel is to be deposited are first
cleansed in a solution of lime and caustic potash; they are then placed
in a solution of ammonia and allowed to remain there a short time;
they are next removed and placed in the vat.
If the solution is found to be not working aright, I put into it
ammoniacal salt in proportion to the amount of solution in the vat, and
if that does not answer the intended purpose, it shows that an ob-
structing cause is at work which may be obviated or removed by the 2
addition of salt of iron; the solution is next to be filtered.
This method of preparing the articles to be coated for the reception of
the nickel gives a fine reguline deposit which may be of any required
thickness, will not strip or peel off, and which will be free from
oxidization or any chemical reaction whatever either upon the metal 2
deposited upon or the metal deposited.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of December, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Unwin, Her special licence
that I, the said John Unwin, my executors, administrators, and assigns,
or such others as I, the said John Unwin, my executors, adminis-
trators, 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 METHOD
OR MEANS OF DEPOSITING NICKEL UPON METALS, AND IN THE PREPARATION OF THE
ARTICLES TO BE COATED FOR THE RECEPTION OF THE NICKEL COATING," upon the
condition (amongst others) that I, the said John Unwin, 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 John Unwin, do hereby declare
the nature of my 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, that is to say:-
My Invention has for its object the depositing on all kinds of metals,
or coating metals with pure nickel in an improved and more efficient
manner than heretofore by the aid of a galvanic current; and my
Invention consists in the employment of a solution prepared in an
improved and different manner from any solution hitherto used for the
deposition of nickel, in the mode of preparing the articles for the
reception of such coating of nickel, and in the method by which the
solution is kept in good working order for any length of time.
In carrying out my Invention I, in the first place obtain a chemically
pure double sulphate of nickel in the following manner :-I take three
parts of nitric acid, one part of sulphuric acid, and two parts of water,
and place the whole in an open pan capable of holding about two

page_text: gallons; I place the pan in a sand bath and apply heat, and when the
acids reach a temperature approaching ebullition, I add four or five
pounds of ordinary commercial grain nickel and continue adding it.
until the acids are saturated therewith; when the acids are saturated, I
evaporate to crystallization and then quickly wash the crystals in cold.
water; when the crystals are washed I put them into a large tub or
other suitable vessel and add boiling condensed water until they are all
dissolved; I then add about two gallons more or less, of sulphate of
ammonia prepared in the following manner :-I take warm water and
add sulphate of ammonia until the water is saturated and afterwards
filtered; I then allow the solution to cool and syphon the clear liquor
off; the solution is then ready for use. I add the prepared solution of
sulphate of ammonia to the boiling solution of nickel until I have
neutralized all the acid in the solution; I then allow the whole to cool,
when the double sulphate of nickel crystallizes upon the sides and
bottom of the tub or vessel; I then pour away the supernatant liquor,
collect the crystals, wash them, and spread them upon paper or other
suitable material to dry.
The above is the method I adopt to obtain my double sulphate of
nickel perfectly pure and free from any foreign and detrimental matter.
My Invention next relates to the method by which I prepare my
solution for the purpose of depositing the nickel. I take the before-
mentioned crystals of double sulphate of nickel and dissolve them in
distilled water heated to boiling until I obtain a saturated solution;
I then allow the whole to cool, when the excess of nickel will collect
upon the sides of the vessel in crystals. I collect the crystals, wash
them with clean cold water, and then add boiling water until all the
crystals are again dissolved. I allow the whole to cool and then add
cold distilled water until the solution is of the specific gravity of 5 by
the acidometer; the solution is then ready for use. If the deposit has a
smoky appearance I add some of the solution of sulphate of ammonia
prepared as before described, and I continue adding the solution of
ammonia until I obtain a good, bright, and reguline deposit.
If after working the solution some time any foreign substance (caused
by the presence of impurities in the anode) gets into the solution and
so spoils its proper working, I take sulphate of iron and add it to the
solution in the following manner, and in or about the following pro-
portions I take two ounces of sulphate of iron to every gallon of

page_text: solution in the vat; I dissolve the sulphate of iron in some of the
solution and then add it to the whole of the solution stirring it well in;
I allow the solution to settle and then syphon off the clear liquor, throw
the bottoms away, and replace the solution in the vat, when it will work
again correctly.
My Invention next relates to the manner in which I obtain my anode
for the depositing bath. I take ordinary grain nickel of commerce, fuse
it with borax, and cast it into plates of the required size, which is a great
improvement upon the old plan of suspending the grain nickel in bags,
nets, &c.
And having now described the nature of my said Invention and in
what manner the same is to be performed, I declare that I claim,―
First. The method substantially as herein-before described of pre-
paring the double sulphate of nickel for the purpose of making a nickel
depositing bath, whereby I obtain a good, tenacious, and reguline.
deposit.
Second. The method substantially as herein-before described, of
making a nickel depositing solution which will be easy to work and
be perfectly neutral to any metal that may be put into it.
Third. The method substantially as herein-before described of pre-
paring my anode for the depositing bath, whereby I obtain a surface
equal to the article receiving the deposit.
In witness whereof, I, the said John Unwin, have hereunto set
my hand and seal, this Twentieth day of May, One thousand
eight hundred and seventy-two.
JOHN UNWIN. (L.S.)