CERTAIN IMPROVEMENTS IN COVERING AND COATING METALS AND ALLOYS OF METALS
Year: 1840

page_text: TO ALL TO WHCM THESE PRESENTS SHALL COME, J, PIERRE
ARMAND LE COMTE DE FONTAINEMOREAU, of Sise Lane, in the City of London,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fifteenth day of August, in the fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Pierre Armand le Comte de Fontainemoreau, Her especial licence, full power,
sole privilege and authority, that I, the said Pierre Armand le Comte de
Fontainemoreau, my exors, adñors, and assigns, or such others as I, the said
Pierre Armand le Comte de Fontainemoreau, my exors, adñiors, or assigns,
should at any time agree with, and no others, from time to time and at II
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, and also in all Her said Majesty's Colonies and Plantations abroad,
the Invention of "CERTAIN IMPROVEMENTS IN COVERING AND COATING METALS
AND ALLOYS OF METALS," communicated to me by a certain Foreigner residing
abroad; in which said Letters Patent is contained a proviso, that I, the said
Pierre Armand le Comte de Fontainemoreau, shall cause a particular descrip-
tion of the nature of the said Invention, and in what manner the same is to be
performed, 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Pierre Armand le Comte de Fontainemoreau, do hereby declare that the
nature of the said Invention consists in improved means for covering or
coating metals and alloys of metals with gold, silver, or platinum, each of the
said last-mentioned metals requiring different media for the accomplishment
of the object. And in further compliance with the said proviso, I, the said
Pierre Armand le Comte de Fontainemoreau, do hereby describe the manner
in which the said Invention is to be performed, by the following statement
thereof (that is to say) :-
First, as to Covering or Coating with Gold.-This process is particularly
applied to copper and its alloys, to silver and its alloys, and to some other alloys
more or less alloyed with copper, to iron, tin, bismuth, antimony, and to the several
alloys of these metals, the process requiring many operations to complete it.
The First Operation consists of the preparation or cleansing of the articles
to be coated. The articles, having been duly formed by the workman in the
shape and form they have to preserve, are at first heated to red heat, then a
little cooled, and after thrown into water lightly acidulated with sulphuric acid;
they remain in that bath until they are perfectly cleaned; they are brushed in
it, and after dried in sawdust; they are then thrown into another bath to give
tliem a fine color, which bath is composed by weight: First, one part of
sulphuric acid; second, one part of water; third, two parts of azotic acid.
When the articles are turning black they are directly taken out and
immediately thrown into some azótic acid, from thirty to thirty-six degrees of
Beaume's arcometer. This turns them a fine yellow color, and as soon as they
have attained that color they are taken and well washed in clean water, dried,
and brushed with a metallic wire brush, and burnished on the parts wanted.
The articles of silver are red heated and thrown into an acidulated bath, into
which they remain three or four hours; as soon as they become white they
are taken out, rubbed with water and fine sand, then washed with clean water,
and afterwards dried; and it may be here observed, that all the other metals
and their alloys should be subjected nearly to the same treatment as a pre-
paratory and cleansing operation.
Preparation of the Gold Solution. Second Operation.-One part of gold (in
weight), which must be very pure and without any silver particles, and of the
smallest parts possible, is dissolved in some brome (bromos), or into some
chlorine, or in some azoto-chloridric acid, or in some azoto-iodydric acid
That solution is made to evaporate till it becomes like syrup. To avoid the
salt of gold volatilising, the evaporation is to be conducted in a glass retort.
Third Operation, which can be performed by one of the five following baths
constituting by themselves five different modes of gilding.

page_text: Four hundred parts (in weight) of distilled water are put into an iron
pot, well enamelled, placed on the fire, and when tepid, seventy parts weight
of hydrated oxide of barium, hydrated barytes, or seventy parts (weight) of
hydrated oxide of strontium, hydrated strontites, are added to them. When
the whole is dissolved, it is scummed if it appears necessary, and then the gold
solution is added. The whole is made slowly to boil till the bath begins to
turn dark purple, and then the article of copper or of any other metals or their
alloys (excepted silver, of which mention shall be made afterwards) is immersed
into it; the article is stirred and is left more or less according to the coat of
gold it has to receive. When taken out it is washed first in water, acidulated
with sulphuric acid or vinegar, and again washed with clean water; then dried
into sawdust, and brushed with the metallic wire brush, and after burnished
on the parts which require it. Care must be taken to add water to avoid the
evaporation of the bath. For the articles of silver they must be covered with
a copper wire or they will not gild.

page_text: Five parts in weight of dissolved gold are precipitated by means of oxide of
zinc. After they are filtered and washed, the precipitated part, that is to say,
what remains in the filter, is put into three hundred parts (weight) of distilled
water, and to them are added two hundred and fifty parts (weight) of chlorine
of barium, barytes, or of strontium, strontites, or of zinc, or of lime, or of
magnesia; the whole is boiled, and the operation is performed. as stated before.
I must here observe, that I prefer using the first of these baths.
Secondly, as to Covering or Coating Metals and their Alloys with Silver.-
The articles having been previously cleansed, as before stated, for gilding two
operations become necessary, namely,―
First Operation. Solution of Silver: Ten parts in weight of pure silver are
dissolved in the azotic acid, and are made to evaporate until the matter
becomes entirely dry. They are then dissolved into distilled water instead of
using the nitrate of silver, which is what has just been obtained. Any other
salt of silver can be used.
Second Operation.-In an iron enamelled pot are put five thousand parts
(in weight) of water, and nine hundred parts (in weight) of chlorine of barium,
barytes, or of sodium, or of strontium, strontites; or of-lime, or of magnesia, or
of zinc, and from one thousand to fourteen hundred parts (in weight) of cream
of tartar, well powdered. When the whole boils the silver solution is added
with twenty-five parts (in weight) of boric, acid. When the bath begins to
concentrate and the salts to depose little, the articles are plunged into it, and
allowed to remain, more or less. They are after taken out, perfectly washed in
tepid water, brushed with the metallic wire brush, dried, and at last burnished
before the last part of the operation. If the coat is not thick enough, the
articles are plunged a second time into the .bath.
Thirdly, as to Covering or Coating Metals and-Alloys of-Metals-with-Platinum.
-The articles having been cleansed as before, a solution of two parts in weight
of platinum is prepared in the acid azotic chlorhydric, or in the brome (bromos),
and when evaporated to the point that it becomes nearly dry, forty parts (in
weight) of distilled water, fifteen parts (in weight) of chlorine of barium (or,
as it is sometimes called, chlorine of barytes), or of strontium, strontites, or of
lime, or of magnesia, or of zinc, or of chloride of ammonia, are added to it.
The whole is made to boil. The articles plunged in that composition take a
grey coating; they are taken out and brushed with the metallic wire brush
and dried. Instead of the chlorine of ammonia, twenty parts of ammonia
dissolved in water can be used. In all cases when the barytes and strontites

page_text: are used in these processes, I prefer them to be prepared by one or other of
the two following manners:-The first consists in using the carbonate of
barytes or of strontites. The carbonate of barytes, which is very common, is
heated very strongly, and is immersed in cold water; the expansion and
contraction which it receives suddenly breaks it into small pieces, and renders
it more easy to be pulverized. It is pulverized and dissolved in as much
of muriatic acid as that acid can dissolve of the powder; that dissolution is
filtered, and nearly as much of hydrate oxide of sodium is poured into it as a s
has been used of carbonate; the barytes is formed, but allowed to cool. It is
then taken with care and lightly washed; afterwards dried without the contact
of the atmospheric air, and it is then in a fit state to be used for coating. Or
the sulphate of barytes, or of strontites, may be pulverized, and four parts of it
mixed with one part of charcoal in powder, and strongly calcined; then left to
cool, and boiled with fifty parts of water, afterwards filtered. Into that
solution, one part of oxide of copper may be put, then boiled and filtered, and
allowed to crystallize, and what remains on the second filtering can be dried by
evaporation, and employed as a new oxide of copper; but in that case three
parts of that oxide and two of a new oxide are the necessary proportions. I
prefer, however, the first process.
And having now fully described the said Invention of covering metals and
alloys of metals, I declare that what I claim as new and as the Invention
communicated to me is,-
First, the use of all the substances I have named in the first herein-before
described process for covering and coating with a coat of gold as well as all
the salts of their bases, either alone, combined, or mixed with other substances;
the substances I claim being the barytes, strontites, lithine, lime, magnesia,
and zinc, and also their salts.
Secondly, in the herein-before described process for covering and coating
with silver, I claim the chlorines of barium, barytes, of sodium, of strontium
strontites, of lime, of magnesia, and of zinc, either alone, combined, or mixed
with other substances, and the described way of operating with the said second
process.
And thirdly, in the herein-before described process for covering and coating
with a coat of platinum, I claim the use of double chlorines of platinum, and
of barium, barytes, and of strontium, strontites, of magnesia, of lime, of
ammonia, and of zinc, either alone, combined, or mixed with other substances.
And I claim also the oxides and the salts of their bases, either alone, com-
bined, or mixed with a salt or an oxide of platinum.
And such Invention being, to the best of my knowledge and belief, entirely

page_text: new, and never before used within that part of Her said Majesty's United
Kingdom of Great Britain and Ireland called England, Her said Dominion of
Wales, or Town of Berwick-upon-Tweed, nor in any of Her said Majesty's
Colonies and Plantations abroad, I do hereby declare this to be my Specifica-
tion of the same, and that I do verily believe that this my. Specification doth
comply in all respects fully and without reserve or disguise with the proviso in
the said herein-before in part recited Letters Patent contained. Wherefore I
hereby claim to maintain exclusive right and privilege to the said Invention.
In witness whereof, I, the said Pierre Armand le Comte de Fontaine-
moreau, have hereunto set my hand and seal, this Seventh day of
September, in the year of our Lord One thousand eight hundred and