IMPROVE- MENTS IN THE MANUFACTURE OF WHITE LEAD
Year: 1876

page_text: LETTERS PATENT to Norman Charles Cookson, of the Town and County of
Newcastle-upon-Tyne, Lead Manufacturer, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF WHITE LEAD."
Sealed the 26th May 1876, and dated the 19th February 1876.
PROVISIONAL SPECIFICATION left by the said Norman Charles Cookson
at the Office of the Commissioners of Patents on the 19th February 1876.
NORMAN CHARLES COOKSON, of the Town and County of Newcastle-upon-Tyne,
Lead Manufacturer. "IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD."
I manufacture white lead by the exposure of a solution of sub-acetate of lead to
the action of carbonic acid gas, and my Invention consists in the manner of such
exposure, namely, I present the liquid to the action of the gas in the state of spray
The liquid, the gas, and the spray separately, may be produced by any convenient
means.
What I claim as my Invention is,―
The combination of the whole three as an improvement in the manufacture of
white lead by the process referred to, the result of my Invention being that the
more perfect the subdivision of the liquid operated upon, and its consequent
exposure to the gas, the more prompt and abundant is the production of white lead.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Norman Samuel Cookson in the Great Seal Patent Office on the 18th
August 1876.
NORMAN CHARLES COOKSON, of the Town and County of Newcastle-upon-Tyne,
Lead Manufacturer. "IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD."
I manufacture white lead by the exposure of a solution of sub-acetate of lead to
the action of carbonic acid gas, and my Invention consists in the manner of such
exposure, namely, I present the liquid to the action of the gas in the state of spray.
The liquid, the gas, and the spray separately may be produced by any convenient
means.
The way in which I prefer to conduct the manufacture is as follows:-I employ
[Price 4d1

page_text: the chamber and apparatus represented on the annexed Sheet of Drawings. The
chamber is simply a large air-tight chamber, strong enough at the bottom to stand
the weight of liquor and precipitated white lead. There are two man-holes at one
side, out of which precipitated white lead is drawn after settling, and clear liquor
run off. To obtain spray I suck carbonic acid with a root blower and force it at a
pressure of a few inches of water through a copper pipe with a long narrow slit.
The sub-acetate is constantly trickling from the smaller pipe and running on to the
sheet of gas escaping, and is blown into the finest of spray. I prefer to use two such
sprays placed at such an angle as when they meet they rise upwards, as shown.
An exhaust pipe should be taken at some convenient place from the chamber, and
the escaping gases should be filtered not to lose any of the acetate of lead which
might be carried away in a spray or finely divided state, such acetate in
practice is used over again for forming a fresh batch of sub-acetate for a further
operation.
The way in which I prefer to prepare the solution of sub-acetate for use is
by treating a solution of the acetate with litharge in the manner described in the
Specification of a Patent, No. 709, bearing even date with that of which this is the
Specification.
The details of the processes of manufacture may be varied; there are many
ways of forming spray and many ways of exposing spray to the action of carbonic
acid gas, but I find the above described form an efficient one by which I can mani-
pulate large quantities in an inexpensive mode. The white lead thus manufactured
may be prepared for the market in the usual manner.
Having thus described the nature of my said Invention and the manner of per-
forming the same, I would. have it understood that I claim, the manufacture of
white lead by the exposure of a solution of sub-acctate of lead in the state of spray
to the action of carbonic acid gas.
In witness whereof, I the said Norman Charles Cookson, have hereunto set
my hand and seal, this Fifteenth day of August in the year of our Lord
One thousand eight hundred and seventy-six.
NORMAN CHARLES COOKSON. (L.S.)