IMPROVEMENTS IN THE MODE OF SILVERING ANIMAL, VEGETABLE, AND MINERAL OBJECTS
Year: 1857

page_text: LETTERS PATENT to Johann Philippe Becker, of No. 51, Rue Doudeau-
ville, à la Chapelle St. Denis, Paris, France, for the Invention of
"IMPROVEMENTS IN THE MODE OF SILVERING ANIMAL, VEGETABLE, AND
MINERAL OBJECTS."
Sealed the 3rd November 1857, and dated the 6th May 1857.
PROVISIONAL SPECIFICATION left by the said Johann Philippe Becker
at the Office of the Commissioners of Patents, with his Petition, on the
6th May 1857.
I, JOHANN PHILIPPE BECKER, of No. 51, Rue Doudeauville, à la Chapelle
St. Denis, Paris, France, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MODE OF SILVERING ANIMAL, VEGETABLE, AND MINERAL
OBJECTS," to be as follows:-
The silvering is effected by bringing the objects in contact with a fluid
composition possessing the quality of acting electro-chemically. This fluid is
formed of metallic or vegetable acids, mixed with water and a solution of
silver, adding thereto according to the natures of the objects to be silvered
and of the bases to be changed, alkalis, grape or milk sugar, chlorine,
fluorine, potassium, calcium, sodium, metallic oxides, and essential oils. The
articles must be well cleansed and freed from obstructing matters by washing

page_text: and soaking them generally in alcohol, a wash of potassium, cyanide of
potassium, or salt of sumac. The solid objects are placed horizontally and
the fluid poured on them, where prompt action is required & sufficient heat is
applied underneath. The electro-chemical action begins after 10 minutes, and
the silvering is completed in about half an hour.
The soft objects are dipped in this fluid, and are exposed to a suitable heat
until the silvering is finished, varying from a quarter of an hour in some to
several hours in others.
The process can be effected with a result nearly the same, if the application
should be applied without the aid of heat, but much more time would be
required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Johann Philippe Becker in the Great Seal Patent Office
on the 6th November 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHANN
PHILLIPPE BECKER, of No. 51, Rue Doudeauville, à la Chapelle St. Denis,
Paris, France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of May in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Johann
Phillippe Becker, Her special licence that I, the said Johann Phillippe
Becker, or my executors, administrators, and assigns, or such others as I, the
said Johann Phillippe Becker, or 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 Invention for "Im-
PROVEMENTS IN THE MODE OF SILVERING ANIMAL, VEGETABLE, AND MINERAL
OBJECTS," upon the condition (amongst others) that I, the said Johann
Philippe Becker, or my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly 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.

page_text: NOW KNOW YE, that I, the said Johann Phillippe Becker, 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 :-
+
The Invention consists in effecting the silvering of mineral, animal, and
vegetable objects by submitting them to certain fluids herein mentioned, so
that by electro-chemical action the object is accomplished.
I prepare, first, a fluid composed of 2 parts by weight of caustic lime, 5 of
grape or milk sugar, 2 of racemic acid (or in place of the latter the same
quantity of carbonic oxide of soda, or potassium, or gallic acid, may be substi-
tuted,) in 650 parts of distilled water. The whole is then filtered, excluded
as much as possible from the atmosphere, and bottled up closely until used.
If there is sufficient time, the acids above mentioned may be dispensed with,
as the caustic lime and the grape or milk sugar will be ultimately dissolved by
the distilled water.
I next prepare fluid No. 2, by dissolving 20 parts of nitrate of silver in
20 parts of liquid ammonia, this is then diluted by 650 parts of distilled
.water.
When required for use the two fluids are put together in equal measures,
& by agitating them freely must be thoroughly mixed; this is then filtered.
Now, as the liquid ammonia of commerce is not always of the same standard,
the proper quantity may perhaps be better determined by dissolving the
nitrate of silver of fluid No. 2 first in the distilled water, then mixing this
product with the first fluid, & then adding thereto as much liquid ammonia as
required for clarifying the mixture thoroughly, taking care not to add too
much, for the reason that the superabounding free ammonia will prevent the
precipitation of the silver. Should this, however, happen, it is to be corrected
by an adequate quantity of the neutralizing silver solution.
In silvering silk, wool, hair, linen, cotton, and other fibrous materials, I
find the following to be the best mode of preparing them:-They are first
thoroughly cleansed, by washing, then immersed for an instant in a solution of
gallic acid saturated with distilled water and allowed to drain off; next, they
are dipped for a second into a solution of 20 parts of nitrate of silver in
1,000 parts of distilled water, and again allowed to drain. This process of
alternately dipping them into the two fluids and draining, as mentioned, is
continued until the blackened appearance of the stuff is followed by a light
silver tinge, when they are immersed in the above compound fluid until com-
pletely silvered, and boiled out in a solution of salts of tartar & water, and
finally washed and dried.

page_text: Bones, horn, wood, straw, wax, cloth, leather, paper, ivory, whalebone,
stone, and similar articles are prepared in the same manner, with this differ-
ence, that instead of being dipped they may be pencilled or brushed with the
solutions of gallic acid & nitrate of silver alternately.
Phosphoric acid, much diluted, may be substituted for gallic acid upon
some of the articles. Flat objects, such as leather, wax, cloth, &c., may be
laid horizontally and have the compound fluid poured over them, and then
rubbed off with tripoli.
Upon leather, tanned with sumac, instead of nitrate of silver chlorine of
silver may be employed advantageously, mixed with some drops of rosemary
oil. Stucco and earthen work is to be treated in the same way after having
been washed over with stearine or varnish, and if very porous, with fluoric or
siluric acid.
To silver glass, chrystal, and china, the article is first thoroughly cleaned
with distilled water and alcohol, and is then treated with the compound fluid.
Hollow vessels may be filled with it, and flat objects may be laid horizontally
and have it poured over them. The latter, such as panes for looking glasses,
may be sunk perpendicularly in cases lined with gutta percha, faced two and
two, & preserved hermetically, the back sides where the silvering is to be
applied being kept apart by any convenient mode, so as to admit the liquid to
come in contact; when thus arranged, the cases are filled with the compound
liquid. After about 15 minutes the precipitation of the silver will com-
mence, and will be completed in some hours time. The silvered sides are
then washed in distilled water, dried in the air or by heat, and covered with
varnish.
The silvering may be accelerated and perfected in a shorter time, say, half
an hour, by creating a temperature proportioned to the nature of the objects
up to 70° Reaumur.
Metal to be silvered must first be cleaned with diluted nitric acid, then
rubbed with a mixture of cyanure of potassium and silver powder, washed
with water, then dipped alternately in liquors No. 1 and 2 until they appear
sufficiently silvered. Iron should first be immersed in blue vitriol.
I do not intend to confine myself to the exact above mentioned proportions,
nor to the exact processes herein-before detailed, as I have given them as the
processes most applicable to the articles enumerated, and which I consider
the most convenient modes of preparing the substances for the electro-
chemical action, and of submitting them thereto.
And now having described my Invention, and the modes in which I would
recommend it generally to be used and applied, what I claim under the herein-

page_text: before in part recited Letters Patent is, the use and application of a compound
fluid, composed substantially as within described, for the purpose of silvering
animal, vegetable, & mineral substances.
In witness whereof, I, the said Johann Phillippe Becker, have hereunto
set my hand and seal, on this Sixth day of November in the year of our
Lord One thousand eight hundred and fifty-seven.
JOH. PH. BECKER. (L.S.)