A NEW COMPOSITION FOR THE PREVENTION OF CORROSION IN METALS, AND FOR OTHER PURPOSES
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUB
WALL, late of Bermondsey, in the County of Surrey, but now of 71, Wapping
Wall, Shadwell, in the County of Middlesex, Surgeon, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Second day of May, in the third year of Her reign, did, for Herself, Her
heirs and successors, give and grant unto me, the said Arthur Wall, Her
especial license, that I, the said Arthur Wall, my executors, administrators,
and assigns, or such others as I, the said Arthur Wall, my executors, adminis-
trators, 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, and also within all Her Majesty's Colonies
and Plantations abroad, my Invention of "A NEW COMPOSITION FOR THE
PREVENTION OF CORROSION IN METALS, AND FOR OTHER PURPOSES;" in which
said Letters Patent is contained a proviso obliging me, the said Arthur Wall,
by an instrument in writing, under my hand and seal, particularly to describe
and ascertain the nature of my said Invention, and in what manner the same
is to be performed, and to cause the same to be inrolled in Her Majesty's
High Court of Chancery, within six calendar months next and immediately
after the date of the said 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, I, the said
Arthur Wall, do hereby declare that the nature of my said Invention, and the

page_text: manner in which the same is to be performed, are described and ascertained
as follows (that is to say):-
I place twenty pounds of the strongest muriatic acid diluted with about three
gallons of water in a shallow pan or or vessel made of cast-iron; I then take
one hundred and twelve pounds of filings of either steel or bar iron or other
wrought iron; I heat them to redness, and throw them into the mixture of
acid and water for the purpose of oxidizing the filings; I then place the pan
on a sand bath (heated by a flue from a furnace) which digests the filings,
and facilitates the oxidation; I repeatedly stir up the whole, and after
subjecting them to this process for about twenty-four hours, or until ebullition
takes place, and the greater part of the filings is taken up by the liquor, or
mixture, I allow the oxides thus obtained to run off through a tap into a
vessel beneath, leaving the metal not operated upon at the bottom; when
these oxides are quite settled, the clear mixture or liquor is run off from them
into a third vessel, and then the filings must be subjected to the same process
in the original mixture to complete the oxidation; (that is) they must
be again made red hot, and the mixture, which has run into the third vessel,
thrown upon them, and this process must be repeated until all the filings
have oxidized that can be made to do so; the oxides thus obtained I now
expose on an iron plate made red hot over a furnace until all moisture has
evaporated from them, and they assume a red appearance; I then mix with
them sixteen pounds of quicksilver, by sifting it through a very fine wire
sieve on to the oxides, and afterwards I intimately mix it with them by
rubbing the whole down in a mortar or other suitable process, and when so
mixed I then add as much water as will cover the surface, and from eight to
nine pounds of strong nitric or nitrous acid, and again place the whole on the
furnace plate or sand bath, and repeatedly stir it until all the menstruum or
liquor has nearly or completely evaporated. I then place the whole mass in a
mortar or other pounding machine, and bray or pound it until it is in a
complete state of blackness; I then mix it with water and stir or wash it
until all the light particles are washed out; I then allow it to settle, and when
the settlement has taken place, the water is poured off from the sediment
at the bottom; this sediment I then place in a crucible or earthen retort,
with a receiver attached adapted for the reception of any chloride or mercury
that may escape or come over [the contents of this receiver I preserve in order
to readd to the general mass afterwards when cool]; then I make it red hot,
and when in this state I plunge it into fresh boiling water and stir it for a few
minutes and then allow it to settle; I then pour the water off, let it cool, and
add the chloride, as before stated; and after the last-mentioned process I add

page_text: to it one-fourth its own weight of common black lead or minium, commonly
called red lead, according to the color which the operator wishes the com-
position to assume. Previously to applying this composition to metals I add to
it such a quantity of a mixture of boiled linseed oil and spirit of turpentine (in the
proportion of one-fifth of spirit of turpentine to the oil used) as will reduce it
to a state sufficiently liquid to be spread with a brush; this preparation I then
apply as thinly as possible, by means of a brush, to sheets of copper or other
metal, which sheets I afterwards subject to a heat gradually raised to about
three hundred degrees of Fahreinheit's thermometer, so as to make the metal
imbibe the preparation. This heat must be applied to the sheets of prepared
metal without smoke or flame by placing the sheets on trucks in contact with
the flue plates, in the manner herein-after described. The mode of applying
this heat may be various, but in order the more distinctly to explain my
meaning and my mode of operation, I hereunto subjoin a Drawing of the
furnace which I use and find to answer the purpose:-I erect two or more
horizontal flues, the construction and dimensions of which may be varied
according to circumstances, which flues should gradually decline towards the
extreme end from the furnace bars, so as to produce a good draught and com-
municate a stronger heat to the plates above next mentioned. These flues
I cover with cast-iron plates; I then raise the exterior walls of the furnace to
the height of about three to six feet above the iron plates, which walls must be
bound with iron braces to prevent them from cracking from the excessive heat;
I then place thin sheets of iron slightly curved, thus forming a roof, and rest
them on the exterior walls. Each end of the chamber (thus formed) is closed
by an iron plate made to slide out and down by a pulley so as to act as a
damper and let out or confine the heat. The heat from the flues is carried
away by a common chimney which has a damper in it for the purpose of
controlling the heat. The sheets of metal prepared with the composition, as
above described, are then placed upon iron trucks, between upright pins, which
run on wheels of four inches in diameter, and are thus placed over the iron
plates made hot by the flues; the heat must be gradually applied, to prevent the
composition from blistering on the metal by the trucks being first placed at the
extreme end from the furnace bars and gradually rolled over the flue plates till
evaporation ceases and the metal assumes a dark appearance;
this completes
the operation. When preparing iron tanks with the composition I apply the
furnace heat merely sufficient at first to expel the moisture from the metal,
and when in that state I take them out and sprinkle over them as much
charcoal very finely pounded as will be absorbed by the metal, which gives to

page_text: the metal when prepared a glossy appearance; I then apply the stronger heat
and the operation is completed.
Now I do not claim as any part of my said Invention any of the separate
processes, or the use of any vessels or furnaces; but I claim as my Invention
the composition, prepared as above described, for the prevention of corrosion
in metals, and for other purposes.
In witness whereof, I, the said Arthur Wall, have hereunto set my
hand and seal, the Fifteenth day of October, One thousand eight