A NEW METHOD OF MAKING WHITE LEAD
Year: 1786

page_text: TO ALL PERSONS TO WHOM THESE PRESENTS SHALL COME, I,
RICHARD FISHWICK, of Elswick, in the Parish of Newcastle-upon-Tyne, in the
County of Northumberland, White Lead Maker, send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of Great Britain, bearing date the
Fifteenth day of January now last past, hath given and granted unto me, the
said Richard Fishwick, my exors, admors, and assigns, His especial licence,
full power, sole privilege and authority, that I, the said Richard Fishwick, my
exors, admors, and assigns, and every of them, from time to time and at all
times hereafter during the term of years therein expressed, shall and lawfully
may make, use, exercise, and vend my Invention of "A NEW METHOD OF MAKING
WHITE LEAD," within that part of His said Majesty's Kingdom of Great
Britain called England, His Dominion of Wales, and Town of Berwick-upon-
Tweed, in such manner as I, the said Richard Fishwick, my exors, admors, or
assigns, shall think fit; in which said Letters Patent is contained (among
other provisoes) a proviso that if I, the said Richard Fishwick, shall not
particularly describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, by an instrument in writing under
my hand and seal, and cause the same to be inrolled in His said Majesty's High
Court of Chancery within one calendar month next and immediately after the
date of the said now reciting Letters Patent, that then the said Letters Patent,
and all liberties and advantages whatsoever thereby granted, should utterly
cease and become void, as in and by the said in part recited Letters Patent,
reference being thereunto had, will more fully appear.
And whereas the general and usual method or process of preparing and
making white lead for many years past has been as follows (that is to say):-

page_text: Within a brick building or any other building covered in and secured from
the weather, spread upon the floor a bed, stratum, or layer of horse litter, two
feet thick or thereabouts, upon which place, close to each other, as many
earthen or other vessels, in size from a pint and a half to six pints each, as can
be placed horizontally upon the surface of the said bed of horse litter. Then
put into each of these earthen or other vessels a wine measure pint of vinegar,
or other acid liquor. Then place or suspend thin sheets or plates of lead,
loosely rolled or folded together in a circular manner, over such vinegar or
other acid liquor, in such manner as not to touch such vinegar or other acid
liquor, such plates or sheets to be perpendicularly placed within the
vessels or otherwise upon the edge thereof, and to be from one sixteenth
of an inch to one fourth of an inch in thickness. The bed, stratum, or
layer to contain in the whole two pounds and a half of lead of avoirdupoise
weight to each or every vessel of vinegar or acid liquor placed upon such bed,
stratum, or layer; the lead and vessels to be then covered over with other
similar sheets or plates of lead laid flat upon the surface thereof, and those
sheets or plates of lead, so laid, covered with deal boards or with straw, which
completes the first bed or stratum. The next bed or stratum, and as many
more as are wanted, may be composed and formed in the same manner as is
above described. Then let the whole contents of the said beds or stratums
remain in the said state until the vinegar or other acid liquor is exhausted or
evaporated, which will generally be in about two calendar months. Then let the
beds or stratums be drawn or taken off and removed, and let the corroded or
white lead be separated from the other part of the lead which remains blue
and uncorroded, and mixed with such a quantity of water as will make it pass
between a pair of millstones, and in that state, let it be ground between a pair of
millstones, and then let the finer parts be separated from the coarser by washing
the same in a large vessel of water, containing five or six successive partitions
or divisions communicating with each other by a small passage at the top, so
that the white lead being pumped, poured, or ladled into the first of the said
partitions or divisions, the finer parts thereof may pass off into the other suc-
cessive partitions or divisions, the last three of which will contain the fine lead,
which must be taken out and put into another back or large tub, to subside,
and then the water should be carefully removed or ladled off; and after a few
days, when the lead is become nearly of the consistence of a paste, it must be
exposed to the air, or to the heat of a stove, in small flat lumps or parcels, of
about seven pounds each, separate from each other, until it is perfectly dry.
NOW KNOW YE, that in compliance with the aforesaid proviso in the
said Letters Patent contained, and for particularly describing and ascertaining

page_text: the nature of my said Invention, and the manner in which the same is to be
performed (having previously described the general or usual method or process
of making or preparing white lead as aforesaid), I, the said Richard Fishwick,
by this Instrument in writing under my hand and seal, intended to be forthwith
enrolled in His said Majesty's High Court of Chancery, do testify and declare
that my said Invention is the substituting in such process for preparing or
making white lead as aforesaid, in the room or place of horse litter, the use of
the common tanners' bark, or of the bark of the oak tree, after the same has
been previously applied or used by tanners for making the liquor or tan which
is used in tanning and preparing hides for leather; and that I have found, by
repeated experiments, that such tanners' bark will communicate a more, certain
and equal degree of heat to the vinegar and lead placed over or upon it than
the horse litter has hitherto been found to do. And I do hereby further
declare that the manner of applying the bark in such method or process of
making white lead, as aforesaid, is to spread upon the floor of such brick
or other building, as aforesaid, a bed of such tanners' bark, as aforesaid, of one
foot thick or thereabouts, in the room or place of a bed of horse litter of two
foot thick or thereabouts, as aforesaid; and so with the next bed or stratum,
and so many more as may be wanted, as aforesaid, adding or applying the other
herein-before mentioned articles, ingredients, or things, in the same propor-
tions, quantities, and manner as is herein-before mentioned or expressed to be
the general or usual method or process of preparing or making white lead.
And I do hereby further declare, that any tanners' bark which will answer
or do for the purpose of making the liquor or tan which is used in tanning or
preparing hides for leather, will also answer and be applicable as a substitute
for horse litter in the process aforesaid.
And forasmuch as my said Invention is the substitution or application of
tanners' bark in the room or place of horse litter in the preparation or making
of white lead (in which tanners' bark has not hitherto been used), therefore if,
in preparing or making white lead, you do use tanners' bark, though the other
ingredients and things made use of and the proportions and manner of using
the same are different from or other than those herein-before described to be
the general or usual method or process of preparing or making white lead
with horse litter, yet nevertheless in such case you do use the Invention which
I do hereby describe.
In witness whereof, I, the said Richard Fishwick, have hereunto set my
hand and seal, this Fourteenth day of February, in the year of our
Lord One thousand seven hundred and eighty-seven, and in the twenty-
seventh year of His said Majesty's reign
F
RICHARD (L.B.) FISHWICK.

page_text: AND BE IT REMEMBERED, that on the Fourteenth day of February,
in the year of our Lord 1787, the aforesaid Richard Fishwick came before
our said Lord the King in His Chancery, and acknowledged the Specifi-
cation aforesaid, and all and every thing therein contained and specified, in
form above written. And also the Specification aforesaid was stampt according
to the tenor of the Statutes made for that purpose.
Inrolled the Fourteenth day of February, in the year of our Lord One
thousand seven hundred and eighty-seven.