SILVERING ALL SORTS OF METALS AND OF GLASS
Year: 1852

page_text: LETTERS PATENT to James Power, Merchant, residing in Paris,
34, Rue de Penthièvre, for the Invention of "SILVERING ALL SORTS
OF METALS AND OF GLASS."
Sealed the 7th May 1853, and dated the 29th December 1852.
PROVISIONAL SPECIFICATION left by the said James Power at
the Office of the Commissioners of Patents, with his Petition,
on the 29th December 1852.
I, JAMES POWER, Merchant, of Paris, 34, Rue de Penthièvre, do
hereby declare the nature of the said Invention for "SILVERING ALL
SORTS OF METALS AND GLASS" by a solution of silver, with the aid of
electricity, and of covering the said coating of silver with a coating
of copper, in the usual way, and in certain cases to detach the
silver & copper plate from the glass, to serve for Daguerreotype,
photograph, and other similar purposes, to be as follows:-
The incessant labours which I have for some years given to the
subject of silvering objects, and the practical experience derived
therefrom, called my attention to experiments upon the productions
of the vegetable world, in comparison with that more beaten track
of mineral substances, the extraordinary reactions of which are so

page_text: well known to scientific men; whereas the substances of vegetable
matter, so extraordinary in their nature and application, have been
heretofore limited almost entirely to the manufacture of varnishes,
and some ordinary qualities of soap.
The study of seeking to operate combinations applicable by their
intimate union in contact with the galvanic battery to produce
effects analogous to the alkaline cyanures, although very different
in their physical aspect, as well as in their chemical reaction in
regard to mineral salts, does not appear to have been thought of up
to the present time.
The substances producing these effects, and which have drawn
my attention particularly, are resinous matters, as rosins, resinous
gums, resinous fluids, and balms. Some idea of the importance of
such a process may be formed, by considering the multiplicity of
bodies contained in this series, and the effects they produce in the
presence of metallic salts, effects totally unknown up to this time,
and which open innumerable advantages to manufacturing and
artistical operations.
The scientific works which treat on resinous matters are extremely
restricted in information as to their reactions; it is evident that
these matters are not simple substances, but formed of several com-
bined rosins; that in this complicated mixture several principles are
totally soluble in the same dissolvent, and starting from this point
produce various effects; whilst, on the other hand, in the presence of
alcali's, the resinous matters combine in all proportions, owing to the
latter being oxygenated bodies; their solidification being due to
this same oxygen, they become acids and act the part towards the
original substances of acids, thus forming soluble resinous matters
with any soluble alcali. This position, however, diminishes, acord-
ing to the nature of the resinous matters; thus this acidity has
caused them to be classed under the heads of negative or acid rosins,
and positive, neuter, or indifferent rosins.
Upon these grounds I have sought to place these products in such
conditions as to prevent a precipitate in the body of the liquour, or
a precipitate of the bodies with which they combine; and to ensure

page_text: that in the presence of oxydable bodies, they may by their own
intimate oxydation impede that of the metals.
Amongst these resinous matters I have sought those which by
their easy dissolution would combine with the liquour, without
causing a precipitate of the metallic salt, and giving at the same
time the effects of metallisation by the battery with the greatest
promptitude.
The resinous matters which I prefer are of the species of resinous
gums, as gum galbanuın, gum ammoniac, assa-foetida, myrrh,
bdellium, euphorbe, gum gutta, olibanum, opoponax, sagapemum,
scammony, &. All rosins properly so called, fluid resinous matters,
and balms give fair results, but in an inferior degree to those
previously indicated. The resinous gums are in the positive sense,
that is to say, of a neuter reaction; thus, to arrive at a complete
combination, it becomes necessary to change the question, and
proceed by means of dissolution. This dissolution, assisted by a
given quantity of alcool, does not produce a precipitate in presence
of the alcali; on the contrary, it facilitates their combination.
Alcool is the most proper dissolvent of resinous matters; it must be
brought to ebullition to produce a complete dissolution of these
resinous matters; in this state it constitutes a resinous spirit
adapted to the silvering process; it then only requires to be filtered.
Preparation of the silvering solution for metals & glass: - Take
one ounce of chrystallized nitrate of silver; dissolve it in twice its
weight of distilled water; add nine and a half per cent. on weight of
nitrate of liquid ammoniac (hartshorne); add six times the weight
of nitrate of alcool (spirits of wine gunpowder proof); agitate the
liquid; measure it; add fifteen per cent on the whole volume of the
liquid of resinous spirit. (This spirit is composed of one part of
resinous matter to five parts of alcool.) I give the preference to
gum galbanum. When the resinous spirit is poured into the liquid,
it becomes white or milky, but gets changed in colour gradually.
Leave it to repose twelve hours, and then filter; measure the
limpid filtered dissolution, and add to it nine times its quantity of

page_text: alcool; agitate the whole for a few minutes, and add eight per cent.
of limpid ammoniac (hartshorne); agitate again, and finally put
an equal quantity of alcool to what your liquid measures.
The
liquid so made will contain about five parts of nitrate of silver
to one thousand parts of liquid; the loss in nitrate of silver in
the operation is, therefore, about one part of the original weight,
and arises from the resinous spirit causing a precipitate during
the combination with the salt or chrystallized nitrate. When
the liquid is made as above described, and filtered, it becomes
clear and of a free colour; the galvanic action does not change
its appearance, and it may be used immediately, but it is prefer-
able to give it time to amalgamate, and to filter it when about to
be employed.
The "anode," or thin sheet of pure silver in communication with
the positive pole, acts perfectly in this liquid, and gradually dissolves
in the bath; the metallisation upon the objects commences imme-
diately on their being put into the liquid, and in a perfectly white
and brilliant form. The quantity of silver upon the glass or metals
can be regulated at pleasure; it adheres strongly, however, upon
certain metals; it may be well to pass those about to be silvered
through a dissolution of nitrate of mercury, to increase its adhesion.
This novel application of resinous matters to nitrate of silver
places my process upon a par with the silvering by aid of cyanures,
the action in the bath being perfectly similar, and producing
precisely the same results.
When operating upon glass in lieu of metals, as glass is a bad
conductor of electricity, I previously place a very thin coating of
silver upon the glass, by adding to the liquid a few drops of spirits
of cloves in a separate bath. I then retire it therefrom, and put it
into the bath connected with the battery as explained for silvering
metals. In acting upon glass the only difference in the composition
of the liquid is, that from two to eight per cent. only of ammoniac
(hartshorne) is used, and this, according to the temperature, or ac-
cording to the quantity of silver desired to be coated, or according to

page_text: the manner of conducting the electric battery: this a skilfull
operator will soon ascertain.
The large quantity of alcoolic spirit introduced into this liquid
has for its object to keep the resinous matters in a state of solution,
to prevent their being precipitated when the addition of ninmoniac
is made, and because this base determines the metallic effect of the
silver upon all objects to be operated upon.
The advantages of this process, particularly as adapted to glass
over all previous systems, arc, that the silvering remains bright, and
docs not change with exposure to damp, or scale off with excessive
heat, as is the case, for instance, with glass reflectors; all previous
means of placing a preservative coating of varnish, &c., over the
silver having been found insufficient. Objects of every shape,
whether of concave, convex, or flat surfaces, can be perfectly
silvered, and when greater solidity is required, a coating of copper
can be added also by electricity, without producing any alteration
in the whiteness or brilliancy of the looking glass, mirror, 01
reflector.
This coating of copper and silver upon the even and polished
surface of glass, on being detached from the latter, forms a inetallic
plate of the most perfect polish, requiring neither flattening or po-
lishing, and is most beautifully adapted to the use of Daguerreotype
and photograph portraits, views, &.; and I therefore include the
producing of these plates in my Invention of silvering upon glass
as a totally novel application, resulting from the process of silvering
glass as above described; this same process will have a similar
result upon all polished surfaces, as porcellaine, or all other earthy
and other substances not metallic susceptible of receiving a perfect
polish.
The use of resinous matters, their effect in contact with galvanic
action in the presence of salts, having hitherto been totally unknown,
I wish it to be understood that what I claim as my Invention is,
The silvering of all metals and glass by the aid of certain com-
pounds, and especially resinous matters, of whatsoever nature or
-

page_text: kind they may be, combined with the use of metallic salts, and put
in contact with galvanic or electric action in the usual way. I
claim the use of all rosins, resinous gums, resinous fluids, and
balms; finally, of all resinous matters or compounds whatsoever.
I further claim, as a totally novel application of silvering upon
glass, the production, without any mechanical process as flattening
or planeing, of electro-chemical plates of a single casting upon
glass, crystal, porcellaine, and all other earthy and other substances
not metallic, susceptible of receiving a perfect polish.
I do not confine myself to the precise details herein described,
provided the peculiar character of the Invention be retained, where-
by silver is deposited upon metals and upon glass, from a solution
of that metal in such manner as to cause the silver to adhere to the
metals and glass, by aid of the substances herein-before described,
and assisted by galvanic or electric action in the usual way.
SPECIFICATION. in pursuance of the conditions of the Letters
Patent, filed by the said James Power in the Great Seal
Patent Office on the 3rd June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JAMES POWER, of Paris, in the Empire of France, and of 16, Castle
Street, Holborn, City, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of December, in
the year of our Lord One thousand eight hundred and fifty-two, in
the sixteenth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said James Power, Her
especial license that I, the said James Power, my executors, ad-
ministrators, and assigns, or such others as I, the said James
Power, 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

page_text: night make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "SILVERING ALL SORTS OF METALS AND OF GLASS,"
upon the condition (amongst others) that I, the said James Power,
by an instrument in writing under my hand and seal, 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.
NOW KNOW YE, that I, the said James Power, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascer-
tained in and by the following statement (that is to say):
For the preparation of the silvering solution for metals: -Take
one ounce of christallized nitrate of silver; dissolve it in twice its
weight of distilled water; add 9 cent. by weight of nitrate of
liquid ammonia (hartshorn); add six times by weight of the nitrate
of silver of alcohol (spirits of wine gunpowder proof); agitate the
liquid, measure it; add fifteen cent. on the whole volume of the
liquid of resinous spirit (this spirit is composed of one part of resi-
nous matter to five parts of spirits of wine). I give the preference
to gum galbanum. When the resinous spirit is poured into the
liquid, it becomes white or milky, but gets changed in colour
gradually. Leave it to settle twelve hours, and then filter.
Measure the limpid filtered solution and add to it nine times its
quantity of spirits of wine; agitate the whole for a few minutes and
add eight per cent. of liquid ammonia (hartshorn); agitate again,
and finally add a quantity of alcohol, or spirits of wine, equal to
what the liquid measures. The liquid so made will contain about
five parts of nitrate of silver to one thousand parts of liquid. The
loss in nitrate of silver in the operation is therefore about one part
of the original weight, and arises from the resinous spirit causing a
precipitate during its combination with the salt or christallized
nitrate. When the liquid is made as above described and filtered,

page_text: •
it becomes clear and of a free colour, the galvanic action does not
change its appearance, and it may be used immediately, but it is
preferable to give it time to amalgamate, and to filter it when about
to be employed.
The "anode," or thin sheet of pure silver in communication with
the positive pole, acts perfectly in this liquid, and gradually dis-
solves in the bath; the metallization upon the objects coininences
immediately on their being put into the liquid, and in a perfectly
white and brilliant forin. The quantity of silver upon the glass
or inetals can be regulated at pleasure. It adheres strongly; how-
ever; to encrease its adhesion upon certain metals, it may be well
to first pass then through a solution of nitrate of mercury.
This novel application of resinous matters to nitrate of silver
places my process upon a par with the silvering by aid of cyanures,
the action in the bath being perfectly similar and producing pre-
cisely the same results.
When operating upon glass, which is a bad conductor of electricity,
1 previously place a very thin coating of silver upon it by adding
to the liquid a few drops of spirits of cloves in a separate bath.
I then transfer it to the bath connected with the battery as ex-
plained for silvering metals. In acting upon glass the only
difference in the composition of the liquid is that from two to eight
per cent. only of ammonia (hartshorn) is used; and this, according
to the quantity of silver desired to be coated, the temperature or
the manner of conducting the electric battery: this a skilful operator
will soon ascertain.
The large quantity of alcoholic spirit introduced into this liquid is
intended to keep the resinous matters in a state of solution to prevent
their being precipitated when the ammonia is added, and because
this base determines the metallic effect of the silver upon all objects
to be operated upon.
The advantages of this process, particularly as adapted to glass,
over all previous systems, are that the silvering remains bright and
does not change with exposure to damp, or scale off with excessive

page_text: heat, as is the case, for instance, with glass reflectors, all previous
means of placing a preservative coating of varnish, &c.* over the silver,
having been found insufficient. Objects of every shape, whether of
concave, convex, or flat surface, can be perfectly silvered; and when
greater solidity is required a coating of copper can be added also
by electricity without producing any alteration in the whiteness or
brilliancy of the looking glass, mirror, or reflector.
This coating of copper and silver upon the even and polished
surface of glass, on being detached from the latter, forms a metallic
plate of the most perfect polish, requiring neither flattening nor
polishing, and is most beautifully adapted to the use of Daguerre-
otype and photographic portraits, views, &c.; and I, therefore,
include the producing of these plates in my Invention of silvering
upon glass as a totally novel application resulting from the process.
of silvering glass as above described; the same process will have a
similar result upon all polished surfaces, as porcelaine or all other
earthy and other substances not metallic susceptible of receiving
a perfect polish.
The use of resinous matters, their effect in contact with galvanic
action in the presence of salts, having hitherto been totally unknown,
I claim as my Invention, the silvering of all metals and glass
by the aid of certain compounds, and especially resinous matters of
whatsoever nature or kind they may be, combined with the use of
metallic salts, and put into contact with galvanic or electric action
in the usual way. I claim the use of all rosins, resinous gums,
resinous fluids, and balms, and all resinous matters or compounds
whatsoever.
I further claim the production as above described of electro-
chemical plates of a single casting upon glass, chrystal, porcelaine,
and all other earthy or other substances not metallic susceptible
of receiving a perfect polish.
I do not confine myself to the precise details herein described,
provided the character of the Invention be retained, whereby silver
is deposited upon metals and upon glass from a solution of that
metal in such a manner as to cause the silver to adhere to the

page_text: metals and glass by aid of the substances herein-before described
and assisted by galvanic or electric action in the usual way.
In witness whereof, I, the said James Power, have hereunto
set my hand and seal, this Thirteenth day of April, One
thousand eight hundred and fifty-three.
Taken and acknowledged by the
within named James Power at
Paris, this Thirteenth day of
April, 1853. Before me,
JAMES POWER. (L.S.)
Her Britannic Majesty's Consul at Paris,
THOMAS PICKFORD. (L.S.)