AN IMPROVED METHOD OF SEPARATING SILVER PROM LEAD
Year: 1833

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HUGH
LEE PATTINSON, of Summer Hill Terrace, in the Parish or Parochial Chapelry
of Saint John, in the County of Northumberland, Agent, send greeting.
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 Twenty-eighth day of October, in the fourth year of His
reign, did, for Himself, His heirs and successors, give and grant unto me, the
said Hugh Lee Pattinson, His especial licence that I, the said Hugh Lee
Pattinson, my exors, admors, and assigns, or such others as I, the said Hugh
Lee Pattinson, my exors, adññors, 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 in
all His said Majesty's Colonies and Plantations abroad, my Invention of
"AN IMPROVED METHOD OF SEPARATING SILVER PROM LEAD;" in which said
Letters Patent is contained a proviso obliging me, the said Hugh Lee
Pattinson, 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 enrolled in
His said Majesty's High Court of Chancery within two 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Hugh Lee Pattinson, do hereby declare the nature of my said Invention to
consist in separating for purposes of commerce the fluid particles of melted
lead containing silver from the solid particles obtained by slowly and gradually
cooling it down, and then draining such solid particles, as herein-after
described.
And in further compliance with the said proviso, I, the said Hugh Lee
Pattinson, do hereby describe the manner in which my said Invention is to be
performed, by the following statement thereof (that is to say) :-
When lead containing silver is very slowly heated or cooled, it divides itself
at a certain temperature into two portions, one of which is quite fluid, while
the other retains or assumes a solid state, or a state approaching to solidity,
and a great part of the silver contained in the original lead goes along with
the fluid portion, leaving the solid portion nearly deprived of its silver. This
principle I have discovered may be applied in various ways to facilitate the
extraction of silver from lead, but the method I have pursued and found to
answer best is as follows:-I melt a quantity of lead in an iron pot, and,
after skimming off the impurities, I allow it to cool slowly, taking care
to break off and mix with the fluid mass from time to time the parts
that may congeal on the sides of the pot. When the temperature has
become sufficiently reduced small solid particles of lead resembling crystals
begin to appear on the surface and in the mass of the melted metal, which
solid particles or crystals, as they continue to form, sink down to the bottom
of the pan, and in a little time are found in considerable quantity. I then
take an iron ladle, perforated with a number of holes, with which I remove
these small particles or crystals of solid lead, allowing the fluid portion to
drain out from among them into the pan. I then place the crystals (either in
the ladle used to remove them from the pan, or in another suitable perforated
vessel) in the chamber of a reverberatory furnace, which is made for the
purpose unusually large, and in this chamber, when heated to a proper tem-
perature, I drain or melt out from among the small solid particles or crystals
a further quantity of fluid lead, leaving the residual lead in the ladle or other
vessel almost entirely deprived of its silver, after which this residual lead is
withdrawn from the furnace, melted in another pot, and cast into pieces for
sale. The lead which drains out from among the crystals in the reverberatory
furnace is from time to time added to the lead in the pan whence the crystals
are taken; in this way I proceed until the original lead submitted to the
operation is reduced to about one third, which, containing nearly the whole of
the silver held by the original lead, is afterwards refined in the usual way.

page_text: The draining of the small solid particles of lead or crystals, after being
removed from the pan in which they are.formed, is an essential part of the
process, as without this the lead, although deprived of a great deal, yet retains
too much of its silver, and this draining is materially facilitated by a slight
agitation of the ladle or other vessel containing the crystals, either by hand or
by machinery, which agitation more completely disengages the globules of fluid
lead as they are formed, and therefore more thoroughily removes the remaining
portion of silver.
The advantages to be derived from my process are as follows:-First, I
am able to separate from lead nearly all the silver it may contain by sub-
mitting only a small part of the lead to cupelation, which very materially
lessens the expence by diminishing the loss of lead and the cost of furnaces,
fuel, and labour; and secondly, I can by my process separate profitably the
silver from lead which has hitherto been deemed unrefinable in consequence of
its containing too small a quantity of the precious metal to. cover the loss of
lead and the expence of extraction in the usual way.
And whereas I claim as my Invention the method of separating silver from
lead herein-before described. And such my Invention being, to the best of my
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, nor
in any of His said Majesty's Colonies or Plantations abroad, I do hereby
declare this to be my Specification of the same, and that I do verily believe
this my said 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 my said Invention.
In witness whereof, I have hereunto set my hand and seal, this Twenty-
third day of December, in the year of our Lord One thousand eight
hundred and thirty-three.
HUGH LEE PATTINSON. (L.S.)
Signed, sealed, and delivered, being first
duly stamped, in the presence of
ARCHIBALD JOSEPHI REED,
Clerk to Messrs. Carr & Jobling, Newcastle-
upon-Tyne.

page_text: AND BE IT REMEMBERED, that on the Twenty-third day of December,
in the year of our Lord 1833, the aforesaid Hugh Lee Pattinson came before
our said Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Inrolled the Twenty-sixth day of December, in the year of our Lord
One thousand eight hundred and thirty-three.