IMPROVEMENTS IN PRODUCING ORNA- MENTAL METAL SURFACES
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, Louis
HYPOLITE PIAGET and PHILIP HENRY DU BOIS, of Wynyatt Street, Clerkenwell,
in the County of Middlesex, 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 Twelfth day of
December (One thousand eight hundred and forty-six), in the tenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said Louis Hypolite Piaget and Philip Henry Du Bois, our exors,
admors, and assigns, Her especial licence, full power, sole privilege and
authority, that we, the said Louis Hypolite Piaget and Philip Henry Du
Bois, our exors, admors, and assigns, or such others as we, the said Louis
Hypolite Piaget and Philip Henry Du Bois, our exors, admors, 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 PRODUCING ORNA-
MENTAL METAL SURFACES;" in which said Letters Patent is contained a proviso,
that we, the said Louis Hypolite Piaget and Philip Henry Du Bois, 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

page_text: 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 thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
Louis Hypolite Piaget and Phillip Henry Du Bois, do hereby declare that
the nature of our Invention, and the manner in which the same is to be
performed, are fully described and ascertained in and by the following
statement thereof, reference being had to the Drawings hereunto annexed, and
to the figures and letters marked thereon, that is to say :-
Our Invention consists of "improvements in depositing metal;" and in
order that our Invention may be most fully understood, and readily carried
into effect, we will proceed to describe the means pursued by us :-
To prepare a bath from which an electrotype plate is to be made, dissolve
fourteen pounds blue vitriol in seven quarts of warm water. Allow this to
become quite cold; then pour it into an earthenware vessel A; this vessel is to
have a plate B of the same material, with one or more holes C, C, perforated
in it, which are to have tubes D inserted, and there is to be another hole E in
the centre of the plate B, through which the model or models to receive the
deposition is or are to be suspended. The plate B is to be fixed in the bath
and is to have pieces of vitriol placed thereon.
PREPARATION FOR THE TUBES D.
Take five pints of water, half a pound common salt, quarter of a pint
of fresh human urine, six drams of sulphuric acid; with this fill the
tubes D, and keep them filled up every six hours; continue this until
the third day, when they will require to be emptied and refilled; then
proceed as before till the deposited plate is as thick as desired. Caro is
to be taken that a drop from the tubes D does not fall into the bath. The
model to be used in the bath (which should be made either of gold, silver,
or copper) is to have soldered on the back a piece of copper wire, which
serves as a conductor. The model (being engraved, engine-turned, or other-
wise ornamented, according to the metal surface it is desired to obtain
therefrom) is to be well cleaned with plumbago and a brush, and its back is
to be fixed in wood, leaving only the required surface exposed. Take a piece
of zinc about five ounces and fasten on a screw; then attach the wire that is
soldered on to the model to the screw, and place the piece of zinc in one of the
tubes D, suspending at the same time the model through the centre hole of

page_text: the plate B into the bath. When the plate is taken out of the bath and
taken off the model, it will exhibit a burnish polish, or dead appearance,
according to the preparation of the model; it will also be found to be good
and pliable metal, bearing to be made several times hot without injuring or
destroying the copy of the finest engine-turning or engraving.
PREPARATION FOR SILVERING.
First dissolve seven hundred drams of sulphate of soda recently prepared
in four parts of warm filtered water; secondly, dissolve twenty-five drams
of carbonate of soda when for use with electric currents, but when to act by
simple immersion,seventy-five drams are used in a pint of warm filtered water;
thirdly, dissolve thirty-one drams of moist carbonate of silver; when these
solutions are cold, mix the sulphate of soda and the carbonate of soda
together; then add the carbonate of silver, and stir all well with a glass stick
till the silver is well incorporated. This preparation is to be used cold. When
electric currents are to be used with the above purposes, we prefer to employ
the battery shewn in the Drawing, which is constructed as follows:-A is a
glass jar; B is a tube of charcoal; C is a porous vessel; and E is a tube of
amalgamated zinc. We have found that in making small articles of silver (or
of gold, as, hereafter explained), such as watch cases, that three such batteries
connected together form a proper strength of battery for the purpose, but for
larger articles more such batteries would be used. Into the vessel A we put
nitric acid and water, mixed in equal quantities; the tube of charcoal B is
introduced into such vessel A, and the porous vessel C is introduced into the
tube B, and the liquid in A should then nearly fill the vessel A. Into the
vessel C we put a mixture of one quarter of an ounce of sulphuric acid, one
ounce of common salt, and two pints of water. The copper bands D of the
three or other number of batteries used are to be connected together, and
then metal connections are to be made between the models which are intro-
duced into the bath to receive precipitations thereon; the copper straps F are
to be connected to each other, and the one from the last battery is to have a
piece of platinum wire soldered at its end, and this platinum wire is to be
dipped for about half an inch into the liquor of the bath.
PREPARATION FOR GILDING.

page_text: water; thirdly, dissolve seven drams of perfectly dry chloride of gold in half
pint of warm filtered water. Take the solution of gold and mix it with the
solution of phosphate of soda; then add the sulphate of soda; care must be
taken that they are well mixed. This preparation is to be used warm but not
boiling. This bath is to be used with electric currents, preferring to use for
this purpose the battery above described for silvering.
PREPARATION FOR GILDING BY IMMERSION.
First, dissolve seven hundred drams of pure pyrophosphate of potash in
five pints of warm filtered water; if this solution is not clear, filter it and let
it remain till it is cold; secondly, dissolve seven drams of dry chloride of gold
in half pint of water; then pour this gently into the pyrophosphate of potass,
taking care to stir it well; this preparation to be used warm. This bath is to
be used in like manner to what has heretofore been done when gilding by
simple immersion without the aid of electric currents.
.
To prepare an electrotype model plate for gilding or silvering after it has
been in the hands of the workmen, first put it in the essence of turpentine
quarter of an hour; then wash and brush it well, after which put it in nitric
acid diluted with water (I use for this purpose half an ounce of nitric acid
of commerce diluted with two pints of water) to take away the oxide; then
place it in cold water, and again brush it with rouge to give brilliancy; place
it next in fresh made human urine for 8 or 10 minutes, and then again in cold
water. The plate is now fit for gilding or silvering by the bath above de-
scribed. By this process a coating of gold or silver will be obtained, which,
when taken from the bath, will only require to be brushed with spirits of wine
and rouge, and in less than half a minute it will be as brilliant as when taken
from the model. It is not necessary to use the scratch brush or to burnish
any part of the plate, which is always required after other modes of gilding
and silvering, and which always injures fine engine-turning and engraving.
Having thus described the nature of the Invention, we would remark that
we do not claim the forming ornamental metal surfaces generally by means of
electric currents, nor do we confine ourselves to the exact details so long as
the peculiar character of either part of our Invention be retained. What we
claim is,―
First, the means herein described of making ornamental surfaces of copper.
Secondly, we claim the producing ornamental surfaces of silver by employing
the bath herein described; and we also claim the employment of the bath
herein described for silvering by immersion.

page_text: And, thirdly, we claim the producing ornamental surfaces of gold by em-
ploying the bath herein described; and also we claim the employment of the
.bath herein described for gilding by immersion.
In witness whereof, I, the said Louis Hypolite Piaget, have hereunto
set my hand and seal, this Twelfth day of May, One thousand eight
hundred and forty-seven.