IMPROVEMENTS IN COATING OR ELECTRO-PLATING IRON, COPPER, BRASS. LEAD, AND OTHER METALS WITH TIN
Year: 1869

page_text: LETTERS PATENT to William Evans Tilley, of No. 6, Kirby Street,
Hatton Garden, in the County of Middlesex, Electro-plater, for
the Invention of "IMPROVEMENTS IN COATING OR ELECTRO-PLATING IRON,
COPPER, BRASS. LEAD, AND OTHER METALS WITH TIN."
Sealed the 25th January 1870, and dated the 26th July 1869.
PROVISIONAL SPECIFICATION left by the said William Evans Tilley
at the Office of the Commissioners of Patents, with his Petition,
on the 26th July 1869.
I, WILLIAM EVANS TILLEY, of No. 6, Kirby Street, Hatton Garden,
in the County of Middlesex, Electro-plater, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN COATING OR ELECTRO-
PLATING IRON, COPPER, BRASS, LEAD, AND OTHER METALS WITH TIN," to be as
follows:-
My Invention relates to the preparation of the bath of tin in which
the metals to be coated or plated are immersed.
It has hitherto been found difficult to keep in solution the oxide of
tin contained in the said bath, the said oxide having a tendency to fall

page_text: to the bottom of the said bath in the form of a precipitate. Now the
object of my said Invention is to remedy this defect.
According to my improvements I prepare the bath of tin as follows:
-I dissolve grain tin in nitro-muriatic acid or in nitric acid (but pre-
ferably the former). I then add to the solution thus formed a solution
of cyanide or ferrocyanide of potassium and water. I then wash and
filter the compound solution thus formed and evaporate the said solution
to dryness or drain it dry in a filter, and add to the compound of cyanide
or ferrocyanide of potassium and oxide of tin as much sulphuric or
muriatic acid as will take them up and hold them in solution, and then
by adding the requisite quantity of water (preferably filtered) I form a
bath in which the articles to be coated are immersed with poles of tin
in the usual way.
The essence of my Invention consists in washing and evaporating or
draining to dryness the compound solution aforesaid, and then adding
the sulphuric or muriatic acid, as described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Evans Tilley in the Great Seal Patent
Office on the 26th January 1870.
'TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EVANS TILLEY, of No. 6, Kirby Street, Hatton Garden, in the County of
Middlesex, Electro-plater 'send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of July, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Evans Tilley, Her special
licence that I, the said William Evans Tilley, my executors, adminis-
trators, and assigns, or such. others as I, the said William Evans
Tilley, 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

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN COATING OR ELECTRO-PLATING IRON, COPPER, BRASS, LEAD,
AND OTHER METALS WITH TIN," upon the condition (amongst others) that I,
the said William Evans Tilley, 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 William Evans Tilley, 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, that is to say:-
My Invention relates to the preparation of the bath of tin in which
the metals to be coated or plated are immersed.
It has hitherto been found difficult to keep in solution the tin con-
tained in the said bath, the said tin having a tendency to fall to the
bottom of the said bath in the form of a precipitate. Now the object of
my Invention is to remedy this defect.
According to my improvements I prepare the bath of tin as follows:-
I dissolve grain tin in nitro-muriatic acid or in nitric acid (but prefer-
ably the former), and thus obtain a solution of nitro-muriate or of
nitrate of tin. I then add to the solution thus formed a solution of
cyanide of potassium and water. The quantity of the solution of
cyanide of potassium added as aforesaid will vary according to the
strength of such solution. The quantity used must be sufficient to
precipitate the tin contained in the nitro-muriate or nitrate solution first
mentioned. I then wash in a suitable filter with water the oxide of tin
thus obtained, and either drain or evaporate it to dryness or (which I
find to answer better) allow it to drain until it is of a pasty or semi-fluid
consistency. I then put the said oxide into an earthenware pan, and
add as much sulphuric or muriatic acid, or sulphuric and muriatic acid
as will take up the oxide and hold the tin in solution. I find in practice
that a mixture of two parts of muriatic acid to one part of sulphuric
acid gives a good result; I then put the solution of tin thus
obtained into the vat or vessel in which the articles to be coated or
plated are to be immersed, and I add to the said solution as much water

page_text: (preferably filtered or soft) as will make a bath of the ordinary strength
used in electro-plating. The bath thus formed is now ready for use, the
articles to be coated or plated being immersed in it with poles of tin in
the usual way.
Having thus described the nature of my Invention, and the manner
in which the same is to be performed, I hereby claim as my said Inven
tion, the preparation of a bath of tin by adding cyanide of potassium to a
solution of nitro-muriate or of nitrate of tin for the purpose of precipi:
tating the tin, and washing and draining or drying the resulting oxide of
tin previously to the addition thereto of the sulphuric or muriatic acid as
described.
In witness whereof, I, the said William Evans Tilley, have here.
unto set my hand and seal, this Twenty-sixth day of January,
in the year of our Lord One thousand eight hundred and
seventy.
Witness,
H. H. MURDOCH,
7, Staple Inn.
W. E. TILLEY. (L.S.)