CERTAIN IMPROVEMENTS IN MAKING OR PRODUCING THE PIGMENT COMMONLY KNOWN BY THE NAME OF WHITE LEAD OR CARBONATE OF LEAD
Year: 1833

page_text: TO ALL TO WHOM THESE PRESENTS SHALL OME, we, JOHN
BAPTISTE CONSTANTINE TORASSA, of Newington Causeway, in the County of
Surrey, Gentleman, PAUL ISAAC MUSTON, of Austin Friars, in the City of
London, Merchant, and HENRY WALKER WOOD, of the same place, Merchant,
send greeting.
WHEREAS, in consequence of a communication from Mr. Emanuel
Montebruno, of Genoa, we are in possession of an Invention of "CERTAIN
IMPROVEMENTS IN MAKING OR PRODUCING THE PIGMENT COMMONLY KNOWN BY THE
NAME OF WHITE LEAD OR CARBONATE OF LEAD;" and whereas His present most
Excellent Majesty King William the Fourth, by His Letters Patent under
the Great Seal of Great Britain, bearing date at Westminster, the Eleventh
day of December, in the fourth year of His reign, did, for Himself, His
heirs and successors, give and grant unto us, the said John Baptiste Con-
stantine Torassa, Paul Isaac Muston, and Henry Walker Wood, our exors,
admors, and assigns, or such others as we, the said John Baptiste Constantine
Torassa, Paul Isaac Muston, and Henry Walker Wood, our exors, adñiors,
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, the said Invention; in which said Letters
Patent is contained a proviso obliging us, the said John Baptiste Constantine
Torassa, Paul Isaac Muston, and Henry Walker Wood, or one of us, by an
instrument in writing under our or one of our hands and seals, particularly to

page_text: describe and ascertain the nature of the said Invention, and in what manner
the same is to be performed, and to cause the same to be inrolled in His said
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said recited 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 of the said proviso, we, the said
John Baptiste Constantine Torassa, Paul. Isaac Muston, and Henry Walker
Wood, do hereby declare the nature of the said Invention to consist in
making or producing the pigment commonly known by the name of white lead,
without the use or employment of vinegar, acetic or acetious acid in any other
form, or under any other name, and without the aid of artificial heat, except
for the purpose of drying the white lead, as herein-after mentioned, by
reducing the ordinary lead of commerce, by friction in water, to a very fine
powder, and then exposing the said powder to atmospheire air, so that it
may acquire both oxygen and carbonic acid, and thus be converted into the
pigment aforesaid. And in further compliance with the said proviso, we, the
said John Baptiste Constantine Torassa, Paul Isaac Muston, and Henry
Walker Wood, do hereby describe the manner in which the said Invention
is to be performed, by the following statement thereof, reference being had to
the Drawing annexed, and to the figures and letters marked thereon (that is
to say):-
We cut common sheet lead into very small pieces or grains, or, what is
preferable, we form lead into what may be termed shot, in the same manner as
patent shot is ordinarily made, except that no ingredient is used to cause the
lead to cool in a perfect round form. The exact shape of the pieces of lead is
immaterial, but the shape of shot is the most convenient. These shots or
pieces of lead we prefer to be about the size of duck shot, and having procured
any given quantity we place them in an open shallow wooden vessel lined with
sheet lead, which we call a friction vessel, covering the bottom of the vessel
with the shot or pieces of lead to the depth of about one inch, and then add
water sufficient to cover them, but not more. We then tip the vessel contain-
ing the shot or pieces of lead from side to side, in such manner as to cause the
shots or pieces of land to roll backward and forward on the bottom of the
vessel, and thus produce great friction of the pieces of lead one against
the other, and this friction will produce an extremely fine powder of lead
mixed with the water, from which it will separate easily if left to subside. We
then remove the moist powder, which is at an early period of the process of a
dark color, pass it through a fine sieve, and expose it for about eight or ten
days to atmospheric air, whilst the powder is still in a moist state and about

page_text: the consistence of thick cream, in another shallow open vessel, which we call
the carbonating vessel, where we agitate or stir it constantly in order to expose
it as much as possible to the action of the atmospheric air, until it assumes
a beautiful white color. It is thus converted into the pigment commonly
known by the name of white lead, or carbonate of lead.
The carbonating vessel may be made of any covenient material, but we
prefer wood as nearly colourless as possible.
When the white lead is thus produced, if it should still contain any moisture,
it should be well dried before it is put into casks for sale.
DESCRIPTION OF THE DRAWING..
Figure 1 is a perspective elevation of a friction vessel such as we prefer
for the purposes of the said Invention. It consists of a shallow box or tray,
lined with sheet lead, turning on a shaft or axis passing under it, which rests
at each end in a slot formed in an upright standard, as shown at A, A. To
these standards are fixed cross pieces B, B, which serve as stops to prevent
the tray from ever tipping or dipping beyond an angle of forty-five degrees.
C, C, are two handles by which the front of the tray is moved up and down by
the operator, the tray turning on its axis as here shown. D, D, are two flaps
or wash-boards to keep the shot or pieces of lead and the water from spilling
over when the tray is in action.
Figure 2 is a side elevation of the same vessel, showing how the operator
stands to work it. The dotted lines show the greatest angle at which the tray
can be placed. And as similar letters are used to denote similar parts in all
the Figures of the Drawing, no further description of this Figure will be
necessary.
Figures 3 and 4 are sections of parts of Figure 2, Figure 3 being taken
longitudinally, and 4 transversely.
Figure 5 is a plan of the friction vessel.
Of the carbonating vessel it is only necessary to say, that a tub, or any other
open and rather shallow wooden vessel, will answer the purpose.
Now whereas we do not claim as the said Invention the form of the friction
or carbonating vessels here given, or the particular manner herein-before
described of agitating the lead, though the foregoing is the process we usually
employ as being the best adapted of any we now know of for the purpose,
when engine power is not used; but we claim as the said Invention he
following improvements (that is say),-
Making white lead without the use of vinegar, or acetic or acetious acid in
any other form, or under any other name, and without the aid of artificial heat,

page_text: except for the purpose of drying the white lead, as herein-before mentioned, and
converting the ordinary lead of commerce into the pigment commonly known
by the name of white lead or carbonate of lead, by reducing it to a fine powder
by friction as aforesaid, and then converting that powder into the said pigment
by exposing it to the atmosphere, as herein-before described.
And such Invention being, to the best of our knowledge and belief,
entirely new, and never before used within that part of His said Majesty's
United Kingdom of Great Britain and Ireland called England, His said
Dominion of Wales, or Town of Berwick-upon-Tweed, we do hereby declare
this to be our Specification of the same, and that we do verily believe this our
said Specification doth comply in all respects fully, and without reserve or dis-
guise, with the proviso in the said herein-before in part recited Letters Patent
contained, wherefore we do hereby claim to-maintain exclusive right and
privilege to the said Invention.
In witness whereof, I, the said Henry Walker Wood, have hereunto set
my hand and seal, this Sixth day of June, One thousand eight hundred