IMPROVEMENTS IN PRODUCING ALUMINIUM AND ITS ALLOYS, AND IN PLATING OR COATING METALS WITH ALUMINIUM AND ALLOYS COMPOSED OF ALUMINIUM AND OTHER METALS."
Year: 1855

page_text: LETTERS PATENT to Frederick Samson Thomas and William Evans
Tilley, of 6, Kirby Street, in the County of Middlesex, for the Inven-
tion of "IMPROVEMENTS IN PRODUCING ALUMINIUM AND ITS ALLOYS, AND IN
PLATING OR COATING METALS WITH ALUMINIUM AND ALLOYS COMPOSED OF
ALUMINIUM AND OTHER METALS."
PROVISIONAL SPECIFICATION left by the said Frederick Samson Thomas
and William Evans Tilley at the Office of the Commissioners of Patents,
with their Petition on the 6th December 1855.
We FREDERICK SAMSON THOMAS and WILLIAM EVANS TILLEY of 6 Kirby
Street in the County of Middlesex do hereby declare the nature of the
Invention for "IMPROVEMENTS IN PRODUCING. ALUMINIUM AND ITS ALLOYS AND IN
PLATING OR COATING METALS WITH ALUMINIUM AND ALLOYS COMPOSED OF ALUMINIUM
AND OTHER METALS" to be as follows,
This Invention consists in depositing aluminium by.electric currents from a
solution of, alumina prepared as hereafter explained with or without other
metals and in plating or coating metals with aluminium and with alloys
composed of aluminium and other metals..
. י …
In order to prepare a proper solution of alumina for the purpose of our
23627-2.

page_text: Invention we place alum of commerce in an iron pot or furnace which we
set over a fire and heat or roast the alum therein until it ceases to boil and
has been reduced to a dry powder by being deprived of its water of crystallization.
We then boil distilled water into which we put the calcined alum and boil
the mixture well we then add cyanide of potassium and boil again then
add distilled water with more cyanide of potassium and boil again for a short
time and then filter the solution which will then be ready to form a bath.
Or in place of the above we dissolve alum in water add thereto ammonia
until it ceases to precipitate. We then put the oxide produced into a filter
and filter it we then wash the oxide with water. We take the washed oxide
from the filter and place it in an iron vessel and add thereto distilled water
more cyanide of potassium and some common salt. The solution is to be
boiled more distilled water is then added and more cyanide of potassium the
solution is then to be again boiled and filtered when it will be ready for the
bath. In preparing the above solution the common salt may be omitted but
we believe it better to use it.
Or in place of the above we can calcine or roast the alum as first described
and boil it with distilled water then add cyanide of potassium and boil again
then add distilled water then boil again and filter then add washed oxide of
'alumina prepared as above described, also more of the cyanide of potassium
and boil until the alumina is dissolved then add distilled water boil and filter
and the solution is ready.
The vessel to contain the bath or solution of alumina may be of any suitable
material we however prefer it to be of iron or of earthenware glazed, and
the solution may be worked hot or cold preferring generally cold. In a bath
of a solution of alumina the articles to be plated are to be suspended by
means of copper or brass or other suitable rods attached to the zinc or nega-
tive pole of a galvanic battery and to the positive pole is attached a piece of
platinum or a pole of aluminium. in addition to which a bag of the oxide
of alumina is to be kept suspended in the bath. By these means the metal
'aluminium will be produced and deposited upon the article placed in the bath.
To plate with the alloy composed of aluminium and silver having set the
bath to work to ascertain that the aluminium is depositing freely we then add
à piece of silver to the positive pole and place the same in the bath or we
suspend in the bath a bag of salts of silver prepared in the ordinary manner
for silver electro-plating and by working with a platinum pole both the metals
aluminium and silver will be deposited the supply of silver can be regulated
according to the quantity intended to be deposited.
8
To plate with an alloy composed of aluminium and tin, a piece of tin is to

page_text: be attached to the positive pole in place of the piece of silver or a salt of tin
may be used in which case the salt of tin preferred is that which is prepared
according to a previously patented process by dissolving tin by nitro-muriatic
acid and nitric acid and then precipitating the tin by an alkali or an alkaline
salt preferably by the ferro-cyanide of potassium. The precipitate is to be
well washed & will then be ready to be placed in a bag and introduced into
the hath and worked with a pole of platinum.
Or in place of the above we take allum which when dissolved we precipitate
with potass, soda or ammonia We then take the oxide of aluminium dissoled
in sulphuric acid or in muriatic acid, we then add distilled water and boil it
with the oxide of tin, filter it and the solution is ready. The strength of this
solution may be sustained by a bag of the oxide of both metals and worked by
a platinum pole.
To plate with the alloy composed of aluminium and nickel we form a bath
of a solution of allumina as before and we attach a pole of nickel or we add
a bag of the oxide of nickel which we prefer to prepare in the following
manner. We dissolve nickel by nitro-muriatic acid and precipitate the same
by ferro-cyanide of potassium we then wash the oxide and it is ready to be
placed in a bag in the bath and to be used with a platinum pole.
To plate with aluminium' and 'iron we use an' aluminium bath. We take
sulphate of iron and dissolve it with water, precipitate with salts of tartar
filter it then. take the oxide of iron and add it to the solution of alumina
boil them together filter and the solution will be ready for use and in
addition to the oxide thus introduced we place some oxide of iron and oxide of
alumina together in a bag and hang them in the bath and employ a pole of
platinum.
To plate with aluminium and copper we use a bath of aluminium as before.
We take the sulphate of copper dissolve it with water precipitate with the
salts of tartar wash the oxide and the oxide is ready. We mix the oxide of
copper with the oxide of alumina and place, in a bag in the bath.
It will be evident that if aluminium be required in the separate state it may
be deposited as above described on a metal which melts at a higher or lower
temperature than the aluminium and then to separate the metal aluminium
by heat when so obtained the metal can be consolidated by processes already
known. We have used the battery of Bunsen of six cells and also the battery
of Smee of 10 cells for a bath of four gallons we however prefer a battery
which has been constructed by ourselves which differs from that of Smee's,
inasmuch as the sheet of platinized silver is enclosed in. a separate porous cell
which prevents, the, oxide of zinc from forming upon or encrusting the

page_text: platinized silver but by which addition the battery retains its power better
we do not however confine ourselves to the use of any particular battery when
carrying out our Invention as above described.
It is to be understood that in all the processes which we have described for
preparing baths of alumina we commence with the alum of commerce because
such is a ready. and convenient form, but the same results are to be obtained
by commencing with various clays or what may be termed the ores of
aluminium or they may be obtained by dissolving metallic aluminium but
as at present aluminium. does not exist as a commercial commodity we prefer
our plan but include the others when found to be available or convenient.
And it is further to be understood that in case of wishing to use two or more
of the metals herein described in a bath of a alumina we introduce them in
such proportions in the baths or in the poles as we think proper.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Samson Thomas and William Evans Tilley in the
Great Seal Patent Office on the 6th June 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME WO FREDERICK
SAMSON THOMAS, and WILLIAM EVANS TILLEY of 6 Kirby Street in the County
of Middlesex send:greeting.
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters
Patent bearing date the Sixth day of December in the year of our Lord One
thousand eight hundred and fifty-five in the nineteenth year of Her reign
did for Herself her heirs and successors give and grant unto us the said
Frederick Samson Thomas. and William Evans Tilley Her special licence
that we the said Frederick Samson Thomas and William Evans Tilley our
executors, administrators and assigns or such others as we the said Frederick
Samson Thomas, and William Evans Tilley our '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
"IMPROVEMENTS IN PRODUCING ALUMINIUM AND ITS ALLOYS AND IN PLATING OR
COATING METALS WITH ALUMINIUM AND ALLOYS COMPOSED OF ALUMINIUM AND OTHER
METALS upon the condition (amongst others) that we the said Frederick
Samson Thomas and William Evans Tilley our executors or administrators

page_text: by an instrument in writing under our or their hands and seals or under the
hand and seal of one of us or them 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 Frederick Samson Thomas on behalf
of myself and 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
This Invention consists in depositing the metallic base of 'alumina 'which
we denominate aluminium by 'electric currents from a solution of alumina
prepared as herein-after explained with or without other metals and in
plating or coating metals with aluminium and alloys composed of aluminium
and other metals.
No. 1. Solution of Alumina.-In order to prepare about 4 gallons of a
proper solution of alumina for the purpose of our Invention we place about
4 lbs. of alum of commerce in an iron pot or crucible which we set over a
fire and heat or roast the alum therein until it ceases to boil and has been
reduced to a dry powder by being deprived of its water of crystallization.
We then boil about 2 gallons of distilled water into which we put the
calcined alum and boil the mixture well. We then add about 2 lbs. of
cyanide of potassium and boil again for about half an hour then add
2 gallons of distilled water with 2 lbs. more of cyanide of potassium and boil
again for a short time and then filter the solution which will then be ready
to form a bath.
No. 2. Solution of Alumina.-Or in place of the above we dissolve about
4 lbs. of alum in water and add thereto salts of tartar until it ceases to
precipitate. We then put the oxide so produced into a filter and filter it;
then wash the oxide with water then take the washed oxide from the filter
and place it in an iron vessel and add thereto about 2 gallons of distilled
water and about 2 lbs. of cyanide of potassium. The solution is then to be
boiled for about half an hour two gallons more water is then to be added and
2 lbs. more cyanide of potassium the solution is then to be boiled again and
filtered when it will be ready to form the bath.
No. 3. Solution of Alumina.-Or in place of the foregoing we dissolve
about 4 lbs. of alum in water and add thereto ammonia until it ceases to
precipitate, after which we follow the same mode and quantities as stated in

page_text: No. 2 the only difference being that aminonia is used to precipitate the
alumina in place of salts of tartar.
No. 4. Solution of Alumina.-Or in place of the foregoing we dissolve
alum in water and precipitate with carbonate of potassium then filter the
alumina then take the alumina and roast it upon an iron plate until com-
pletely dry. We then place in an iron pot or crucible about 4 lbs. of cyanide
of potassium which we completely melt we then add about 1 lb. of the dried
alumina and melt this with the cyanide we then add (by degrees to prevent
too violent an ebullition) about a pound of carbonate of soda and we fuse
these three ingredients together about one minute at a red heat. We then
place the mixed ingredients in about 4 gallons of water then boil and filter
and the solution is ready. The vessel to contain the bath solution of
alumina may be of any suitable material we however prefer it to be of iron
or of earthenware glazed and the solution may be worked hot or cold. In
general we prefer cold in the earthen vessel to produce whiteness of colour in
the aluminium and hot in the iron vessel to obtain increased quantity of the
deposit. In a bath of the alumina the articles to be plated are to be sus-
pended by means of copper or brass or other suitable rods attached to the
zinc or negative pole of a galvanic battery and to the positive pole is to be
attached a piece of platinum or a pole of aluminium. In the case of a
platinum pole the metallic property of the bath is to be sustained by sus-
pending therein a bag of the oxide of alumina and replacing such from time
to time with fresh alumina or by adding the solution of alumina from
time to time. In working aluminium baths of various dimensions we have
used the battery of Bunsen of six cells and also the battery of Smee of ten
cells. We find the aluminium will deposit at various powers slowly under a
weak power but rapidly and almost instantaneous under a strong power and
without oxydizing. In working with other metals in a bath of alumina we find
it best to regulate the battery power according to the usual process of electro-
plating, the criterion as far as we can advise being a sound metallic deposit
without oxide. We find however that Smee's batteries are subject to much
fluctuation and occasional suspension of power we therefore prefer a battery
which has been constructed by ourselves which differs from that by Smee
inasmuch as the sheet of platinized silver is enclosed in a separate porous
cell which prevents the oxide of zinc from forming upon or encrusting the
platinized silver at least for a far greater time by which addition the battery
becomes more steady and retains its power longer. We do not however
confine ourselves to the use of any particular battery or arrangements of
magnets when carrying out our Invention.

page_text: No. 5. To plate with an Alloy composed of Aluminium and Silver or with
Aluminium Silver and Copper.-We use for this purpose a bath composed
of alumina made according to the processes described in Nos. 1. 2.or 3 but
we prefer No. 3 and having, set the bath to work with a platinum pole to
ascertain that the aluminium will deposit we insert in lieu of the platinum
pole a pole of silver usually lessening the battery power and the deposit
should become whiter and thicker. When we wish to incorporate copper we
use a pole composed of silver and copper melted and rolled together in such
proportions as we think proper. . We have found equal proportions of silver
and copper deposit a very white metal similar in appearance to standard
silver beyond that proportion of copper we have found the deposit of a
reddish tint. In the bath of alumina No. 3 the oxides of silver or of silver
and copper may be introduced but we consider it preferable to work the
silver or the silver and copper from the poles as described in the bath of
alumina. The battery power in this bath should be moderate...
No. 6. To plate with an Alloy composed of Aluminium, and, Tin. We make
a bath of alumina,according to any of the foregoing methods preferably
No. 4 and instead of using a platinum pole we use a, pole, of tin. The baths
of the alloy of tin will work with various battery powers the deposit will be
thicker for the presence of tin and the presence of aluminium will be known
by the deposit taking a good burnish which tin alone will not sustain. We
sustain the bath by adding alumina in solution. from time to time. the. tin
being supplied from the pole. Or in lieu of this mode we prepare the
alumina according to the mode specified in No. 4 until all the ingredients for
the alumina are fused together. We then take 4 oz. of metallic tin dissolve
it with nitro-muriatic acid precipitate with salts of tartar dry the oxide then
add it to and fuse it with the fused alumina for about half a minute pour the
fused mass upon a slab then put the whole into about 4 gallons of distilled
water boil it and filter it and the solution is ready. This bath may be
worked with a platinum pole in which case both alumina and the oxide of tin
are to be supplied from time to time or it may be worked with a tin pole in
which case the alumina alone is to be supplied in solution. Or in place of
the above we take alum which when dissolved we precipitate with potass
soda salts of tartar or any, suitable alkali. We then dry the alumina on an
iron plate. We then take the dried alumina and fuse it with cyanide of
potassium and carbonate of soda and also fuse therewith oxide of tin. This
is then turned out upon a slab dissolved in water then boiled and filtered
and the solution is ready. This solution may be worked and sustained in the
same modes as the former.

page_text: 10 plate with the Alloy composed of Aluminium and Nickel. We form a
bath of alumina according to the solution No. 3 and we attach a pole of nickel
with which we work the bath supplying the alumina in solution from time to
time. A strong battery power may be used for the baths of nickel but they will
work with various powers. Or we add to the bath of alumina a bag of the oxide
of nickel which we prepare in the following manner. We dissolve nickel by
nitro-muriatic acid say one part muriatic and two parts nitric and precipitate
by ferro-cyanide of potassium we then wash the oxide and it is ready to be
placed in the bath. If this bath be used with a platinum pole both the oxides
must be supplied from time to time. If with a nickel pole the alumina alone
must be supplied in solution. Or we take about 4 ounces of nickel which we
dissolve with nitric acid and precipitate with carbonate of potassium we then
take the oxide so produced with about 4 lbs. of carbonate of ammonia and
4 gallons of distilled water to this we add about lb. of the oxide of alumina
prepared according to No. 3 boil in an iron vessel filter the solution and
then it is ready for the bath which we work with a nickel pole.
No. 8. To plate with Aluminium and Copper.-We dissolve alum in
water and precipitate either by carbonate of potassium or carbonate of am-
monia we then filter the alumina then take the alumina and roast it upon
an iron plate until dry we then place about 4 lbs. of cyanide of potassium
in an iron crucible and completely melt it we then add about 1 lb. of the
dried alumina and melt this with the cyanide we then add (by degrees so
as to avoid too violent an ebullition) about 1 lb. of carbonate of soda and we
fuse these three ingredients together about one minute at a red heat we then
take about lb. of the sulphurate of copper which we add to the fused
alumina and again fuse it with copper until both are melted then turn it out
on a slab, then place the compound in about 4 gallons of water boil it and
filter it and the solution is ready. This solution should produce a deposit of
a reddish purple having the red color of copper influenced by the aluminium.
This bath may be worked with a platinum or a copper pole. In the former
case the bath must be replenished with the oxides of both metals in the latter
case with alumina in solution only.
No. 9. To plate with Aluminium Copper and Zinc.-We take half a
pound of the sulphate of zinc which we fuse with the alloy of alumina and
copper as described in No. 8 introducing the sulphate of zinc next after the
copper has been fused with the alumina and we then proceed to complete the
solution as in the foregoing. We then try the bath to ascertain if there has
been a change in the colour from the former red colour produced by the bath
of copper and alumina to a colour more resembling gold or brass. If it be

page_text: not sufficiently changed to a yellow tint which should be the effect of the
sulphate of zinc we add some oxide of zinc and a further portion of cyanide
of potassium. It is preferred to work this bath with a pole of brass supplying
alumina in solution from time to time and we have found the same results
from various powers of the battery.
No. 10. To plate with an Alloy of Aluminium Silver and Tin.-The bath
of alumina is made in the same manner as No. 4 with the exception of using
8 lbs. of cyanide of potassium in lieu of 4 lbs. We then take 8 ounces of
metallic tin dissolve it with nitro-muriatic acid precipitate with salts of tartar
and dry the oxide. We then take 4 oz. of silver dissolve by nitric acid pre-
cipitate by salts of tartar dry the oxide we then melt the cyanide of potassium
in an iron pot we then fuse the alumina and carbonate of soda as described
in No. 4 then add the oxides of silver and tin to the hot liquor let it remain
a few minutes dissolve it in about 4 gallons of distilled water boil the solution
filter it and it is ready for the bath. This solution may be worked with a
platinum pole in which case the oxides of all the metals must be supplied or
it may be worked with a pole of silver and tin in which case the alumina.
alone must be supplied and a moderate battery power should be employed.
No. 11. To plate with Aluminium and Iron.-We use a bath of alumina
prepared as before named then take sulphate of iron and dissolve it with
water precipitate with salts of tartar filter it then take the oxide of iron
and add to the solution of alumina in the proportion of about 1 lb. of the
oxide of iron to 4 gallons of the solution of alumina boil them together filter
and the solution will be ready for use. This bath may be worked with a
platinum pole and the strength of the bath is sustained by adding the oxide
of aluminium and the oxide of iron from time to time. If aluminium or the
alloys of aluminium with other metals be required in a solid state it or they
may be deposited as before described on a metal which melts either at a
higher or lower temperature than the aluminium or the aluminium and its
alloys or upon a metal that is harder than the deposit and the deposit can
then be separated by heat or by scraping and the aluminum or aluminum
and its alloys so obtained can be consolidated by processes already known.
It is to be understood that in all the processes which we have described for
preparing baths of alumina we commence with the alum of commerce because
we have found such to be a ready and convenient form but the same results
are to be obtained by commencing with what may be termed the ores of
aluminium.
Having thus described the nature of our Invention for plating with the
before-named metal and alloys of that metal with other metals we would have

page_text: it understood that we do not confine ourselves to the precise proportions nor to
the details of the processes herein described nor do we claim generally the
preparation of baths from alumina we having in the Specification of a Patent
granted to us on the Twenty-sixth December One 'thousand eight hundred
and fifty-four described the use of alumina in making a bath to be used in
depositing by electricity the metallic base but what we claim is the prepa-
ration of baths of alumina and depositing therefrom by electricity the
metallic base thereof with or without other metals in alloy therewith as
herein described.
In witness whereof I the said Frederick Samson Thomas have hereunto
set my hand and seal this Fifth day of June in the year of our Lord
One thousand eight hundred and fifty-six.
Witness
S. CARPMAEL.
FRED. S. THOMAS. (L.B.)