IMPROVEMENTS IN MANUFACTURING A CERTAIN COMPOUND OR CERTAIN COM- POUNDS OF LEAD, AND THE APPLICATION OF A CERTAIN COMPOUND OR CERTAIN COMPOUNDS OF LEAD TO VARIOUS USEFUL PURPOSES
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HUGH
LEE PATTINSON, of Washington House, Gateshead, in the County of Durham,
Chemical Manufacturer, send grecting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fourteenth day of
February, One thousand cight hundred and forty-nine, in the twelfth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Hugh Lee Pattinson, my exors, adñors, and assigns, Her especial licence,
full power, sole privilege and authority, that I, the said Hugh Lee Pattinson,
my exors, adñiors, and assigns, or such others as I, the said Hugh Lec
Pattinson, my exors, adññiors, 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, my Invention
of "IMPROVEMENTS IN MANUFACTURING A CERTAIN COMPOUND OR CERTAIN COM-
POUNDS OF LEAD, AND THE APPLICATION OF A CERTAIN COMPOUND OR CERTAIN
COMPOUNDS OF LEAD TO VARIOUS USEFUL PURPOSES;" in which said Letters
Patent is contained a proviso that I, the said Hugh Lee Pattinson, should
cause a particular description of the nature of my said Invention, and

page_text: in what manner the same is to be performed, by an instrument in writing
under my hand and seal, to be inrolled in Her said Majesty's High Court of
Chancery within six calendar months next and immediately after the date of
the said in part 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 with the said proviso, I, the said
Iugh Lee Pattinson, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully described
and ascertained in and by the following statement thereof, that is to say :-
I have discovered that when half an equivalent or thereabouts of lime, soda,
potash, ammonia, or barytes, is added to one equivalent of chloride of lead,
both in solution, the whole of the lead is precipitated as a definite compound
of one atom of chloride and one atom of hydrated oxide of lead, which, when
dried at two hundred and twelve degrees or under, has the composition
just stated, or Pb, Cl+PbO, H O, but when dried at from 212° to 350°,
it loses more or less of the atom of water, and becomes or approaches
Pb, Cl+PbO. If less than half an equivalent of the alkaline precipitant is
employed, the same definite oxichloride of lead is precipitated, and some of
the chloride of lead remains in solution. This oxichloride of lead is of a
brilliant white color, and possesses great body qualities, which render it an
excellent pigment, and suitable for most purposes to . which white lead is
commonly applied. Now, my Invention consists of the manufacture and appli-
cation to useful purposes of this oxichloride of lead, or such other compounds
of oxide and chloride of lead as shall result from the mode of manufacture to
be presently described.
And I do hereby further declare, that the best mode of carrying my
Invention into practise, as it has appeared to me, is as follows:-Of the
alkaline substances just mentioned I decidedly prefer to use lime, because it
answers equally as well as soda, potash, ammonia, or barytes, and is much
cheaper. When using lime, I make a saturated lime water by throwing an
excess of slacked lime into a tank, filling the same with water, plunging the
whole up sufficiently, and allowing it to settle till clear. This lime water made
at the ordinary temperature of fifty-five degrees or sixty degrees of Fahrenheit
will contain in 770 or 780 parts one part of lime, and therefore one cubic foot
will contain 567 or 568 grains of lime. I also make a solution of chloride of
lead by dissolving it at the rate of 1 lb. of pure crystallized chloride of lead
in one cubic foot and one fifth of boiling water, for which purpose I have
a strong wooden barrel of about 150 feet capacity, provided with a revolving
agitator moved by engine power, and into this barrel filled with boiling water

page_text: I introduce 125lbs. of pure chloride of lead; but as common water always
contains some earthy salts, sulphates or carbonates, or both, which preci-
pitate lead, I add such an excess of the chloride of lead as by previous trials
I find will make up for this loss, so as to allow each cubic foot and one
fifth the solution to hold, dissolved, as near as may be, one pound of chloride of
lead, or 5833 grains per cubic foot. After it is run out of this dissolver into a
suitable cistern, fully settled and quite clear, I now mix the clear solution of
chloride of lead while still hot or warm (because if suffered to become quite
cold it would deposit some of the chloride of lead) with an equal bulk of the
lime water, effecting the mixture as rapidly as possible, when the insoluble
oxichloride of lead is immediately formed, and speedily settles to the bottom of
the cistern into which the mixture is run, leaving a clear supernatant liquor
(a weak solution of chloride of calcium), which may be afterwards witlidrawn,
and the precipitate collected and dried in the usual way. The method of
mixing the solution of chloride of lead and lime water I practise, and find to
answer well, is to have two tumbling boxes, each of about sixteen cubic feet
capacity, which are filled with the two solutions, and simultaneously upset
into a lower cistern, in which the oxichloride is instantly formed, and from
which the mixture flows into settling cisterns, where the oxichloride subsides.
Now one cubic foot of saturated lime water, containing about five hundred aud
sixty-eight grains of lime, and one cubic foot of the solution of chloride of
lead described, containing 5883 grains of chloride of lead, also an equivalent
140 of chloride of lead, requiring about half an equivalent 14 of lime, or one
tenth of its weight, to convert the whole of the chloride of lead into the neutral
oxichloride Pb, C+ PO, it is apparent that rather less than the atomic
proportion of lime has been employed; but I have thought it better when
operating in the large way to have the lead a little in excess, for when the full
half equivalent of lime is used, owing to the difficulty of intimately and
rapidly mixing large masses of different fluids, the oxichloride produced
occasionally contains a slight excess of oxide by which its colour is somewhat
impaired, while no disadvantage is sustained by having a slight deficiency of
lime, except that a little chloride of lead goes away in the clear liquor, and
this may be recovered by suffering the clear liquor to flow into a tank, and
throwing down the excess of lead by adding a little more lime water or any
other suitable precipitant. If, however, it is considered desirable to avoid this
second precipitation, the full half atom of lime (or the exact quantity required
to throw down the whole of the lead) may be used at once, and should there
at first be an excess of oxide in the precipitate, and consequently a little

page_text: chloride of lead in the clear liquor, by stirring up the precipitate among the
clear liquor before any of the latter is withdrawn, and agitating the whole well
together a few times, the excess of oxide is converted into the oxichloride, and
on settling the clear liquor will be found quite free from lead.
I have described the use of pure crystallized chloride of lead, but it is not
essential to have it in this form, for rough chloride made from lead orc, and
its equivalent of muriatic acid boiled to dryness, will answer, provided it is
well washed, so as to be freed from chlorides of iron, manganese, or other
bodies likely to injure the colour of the oxichloride to be produced from it.
When rough chloride is employed, it is of course necessary to have the
proportion of pure chloride contained in it exactly determined beforehand,
in order that the proper quantity may be used in the dissolver. If, however,
a solution of chloride of lead of uncertain strength is obtained, or lime water
not quite saturated, they can be used with little disadvantage; for it is only
necessary to be careful not to add an excess of lime (that is, not more than
the half equivalent), which can be easily socured after a few trials by filling
the lime or lead tumbling box more or less with its respective solution as
the trials may direct.
It will not be necessary to detail any particular mode of proceeding
with soda, potash, ammonia, or barytes, for if ever it should happen that
these bodies could be used in preference to lime, it would obviously be
necessary merely to make a solution of each of known strength, and to use it
with chloride of lead in the way already fully described as applying to lime.
Having thus described the nature of my Invention, and detailed the
mode in which it may be carried into operation, I claim the manufacture
of oxichloride of lead, having the composition of one atom of chloride of
lead and one atom of oxide of lead, with or without an atom of water (or an
oxichloride of lead as near this composition as the nature of the manufac-
turing operations may admit), by the use of chloride of lead and lime, soda,
potash, ammonia, or barytes. And I claim the application and use of this
oxichloride of lead as a white paint, as a base for colored pigments, as an
adhesive cement for joints, and for many other purposes to which white lead
is commonly applied.
In witness whereof, I, the said Hugh Lee Pattinson, have hereunto
set my hand and seal, this Twenty-eighth day of July, in the year of
our Lord One thousand eight hundred and forty-nine.
H. L. (Ls.) PATTINSON.

page_text: AND BE IT REMEMBERED, that on the Twenty-eighth day of July,
in the year of our Lord 1849, the aforesaid Hugh Lee Pattinson came
before our said Lady the Queen in Her 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.
Enrolled the Eleventh day of August, in the year of our Lord One
thousand eight hundred and forty-nine.