IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD
Year: 1837

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, CHARLES
BUTTON, of Holborn Bars, Chemist, and HARRISON GREY DYAR, of Mortimer
Street, Cavendish Square, Gentleman, both in the County of Middlesex, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by
Her Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Twenty-third day of December, in the first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
us, the said Charles Button and Harrison Gray Dyar, Her especial license,
that we, the sail Charles Button and Harrison Grey Dyar, our exors,
adñiors, and assigns, or such others as we, the said Charles Button and
Harrison Grey Dyar, our exors, admors, 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, our Invention of "IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD;"
in which said Letters Patent is contained a proviso obliging us, the said
Charles Button and Harrison Grey Dyar, by an instrument in writing under
our or one of our hands and seals, particularly to describe and ascertain the
nature of our said Invention, and in what manner the same is to be performed,
und to cause the same to be enrolled in Her 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, we, the said
Charles Button and Harrison Grey Dyar, do hereby declare the nature of
our said Invention to consist,-
First, in purifying the gases or vapours arising from anthracite coal, or
from stone or mineral coal, or from coke, so that either of these kinds of fuel
may be used instead of charcoal in the process of manufacturing carbonate of
lead, the said purification being effected by a process of burning and of washing
herein-after explained.
Secondly, in the use of basic nitrates of lead for producing carbonate of
lead. And,
Thirdly, in causing white lead to be made from litharge, massicott, or pro-
toxide of lead, by boiling nitrate of lead stirred up witheither of those substances,
and exposing the mixture while hot to be acted upon by carbonic acid gas.
And in further compliance with the said proviso, we, the said Charles
Button and Harrison Grey Dyar, do hereby describe the manner in which our
said Invention is to be performed by the following statement thereof, reference
being bad to the Drawing annexed, and to the figures and letters marked
thereon, that is to say :—
First, as to the machinery orapparatus used for our improvements in the said
manufacture.
Figure 1 is a vertical section of the apparatus in use, so far as it is
necessary in producing white lead from litharge, massicott, or protoxide of
load. A is a pair of forge bellows. B the rod by which the bellows
-
are kept in action. C is a weight or load on the bellows, necessary to
overcome the friction and heads of water or solutions against which
they have to contend. D is a safety valve on the bellows. E is the
nozel pipe of the bellows going into the furnace F, which is a cast-iron
vessel. t is a cast-iron cap or cover which can be taken off at pleasure.
c is a bridle of wrought iron through which the screw works, so as to
fasten the covert, which we make air-tight with a little fire-clay. G is the
exit pipe of the flame from the furnace. 11, I, is an iron chamber which may
be designated as the flamechamber, and in which the vapours or gases passing
from the furnace are burnt. Kis the exit pipe from the flame chamber. Lisa
plug (which may be unscrewed in case the pipe G be obstructed) by which
tke passage can be freed from dust. At H and I are two caps which. may
be unscrewed so as to removeauyaccumulation of dust which might collect in
the flame chamber. M is a pipe leading from the nozel of the bellows round

page_text: one side of the furnace into the flame chamber, which pipe will convey
atmospheric air from the bellows into the flame chamber, without going
through the furnace F. The arrangements of this pipe in its rotation to the
furnace and flame chamber may be more fully understood by referring to
Figure 2, which is a horizontal section of the furnace, flame chamber, the
pipe M, and the nozel of the bellows, similar letters being used to denote
similar parts in this Figure and in Figure 1. But to revert to Figure 1, at
Nand O are cocks, the one in the nozel of the bellows, the other in the pipe.
leading from the bellows to the flame chamber, and the area of the opening
in the latter cock should be one fifth of that in the former.
P is a large
closed cylindrical iron vessel which may be denominated the washing vessel,
into which the burnt gases or products from the furnace pass. Q, R, is a
plate of iron: T, T, T, show the sections of a spiral coil of flat sheet iron open
at bottom and attached vertically to the plate Q, R, in such a manner that the
air may enter the outermost part of the coi! at R, and circulate round the coil
until it arrives at the centre S, at which place there is an opening through the
plate Q, R, by which the vapours and gases may pass into the upper part of the
vessel P. Figure 3 is a horizontal section of the coil T, T, T, shewing that
the burnt vapours or gases may enter at R and circulate round the coil
and pass out at S, similar letters denoting similar parts in this Figure and in
Figure 1. U, U, is a diaphragm of fine wire gauze drawn across the washing
vessel P, and supported by perforated copper plates. V and Ware cocks.
X is a funnel with cock attached. Y, Y, Y, is a shaft and arms of a stirrer
worked through a stuffing box at Z. The burnt vapours and gases after'
passing first through the coil T, T, T, then through the wire gauze 'U, U,
makes its exit through the pipe a. b and c are two cylindrical copper vessels.
d, d, d, d, are copper jackets or casings inclosing the copper vessels b and c
e, e, e, e, are steam-tight vacaut spaces between the said jackets and the said.
copper vessels. f is a steam pipe opening into theso vacant spaces. g is
an exit pipe for condensed water. h, h, are air cocks. The copper
vessel c may be designated as the white lead vessel, the copper vessel b
may be designated the litharge, massicott, or protoxide of lead vessel.
i, i, i, i, is a copper pipe coiled round the bottom of the vessel c,shown in plan
at Figure 4, the one end being closed and the other connected with the pipea.
The coil i, i, i, i, is pierced with a great number of small holes, so that the
vapours a and gases passing down the pipe a to the coil i, i, i, i, will pass out of
that coil in a great number of little streams or bubbles into the open vessel c.
k, k, k, k, is the shaft and arms of a stirrer or agitator working in the litharge
vessel c. l, m, are two copper pumps drawing out of the vessels cand by

page_text: means of the coppor suction pipes n and o, and discharging through the pipes
and g into the filtering bags r and s. The filtering bags and 3 are coarse
linen cloth or sheeting stretched on square wooden frames t, t, t, t.
Secondly, as to the mode of working. this apparatus. We remove the cap
or cover from the furnace F, and we then throw a little lighted fuel into the
furnace, at the same time setting the bellows A in action, the cock N being
open and cock O being closed. We then fill up the furnace with the best
anthracite or stone coal or coke, for bituminous coal if used at all should be
first coked; after the fire is well lighted we put on the cap t and screw it
down air-tight. We then turn on the cock O. We allow the coal in the
lower part of the furnace, at and below the pipe G, to become completely
ignited before the gas is applied to use, after which the volatile matter liberated
from the coal, which lies in the furnace above G, will be very much decom-
posed in passing through the ignited coal lying about the pipe G before it
escapes into the flame chamber H, I; by this means when it escapes into the
flame chamber it is at a very high degree of temperature, and it is then
intersected by and mixed with a fresh portion of atmospheric air, which must
then be allowed to pass from the bellows through the pipe M into the flame
chamber, which fresh supply of atmospheric air is so proportioned in quantity
to that which passes through the furnace as to insure the conversion of any
sulphuretted hydrogen into sulphurous acid and vapour of water, and the
carbonic oxide into carbonic acid,and any compounds of carbon and hydrogen
into carbonic acid and water; at the same time that the operator should
carefully prevent such an excess of atmospheric air from passing through the
pipe M as to endanger the sinking of the temperature of the gases in the
flame chamber below that temperature at which sulphuretted hydrogen or
other volatile matter will combine with the oxygen gas in the atmospheric air.
Into the washing vessel P, before the diaphragm of wire gouze U, V,
is inserted or the cover is put upon it, we put a mixture of equal parts of
carbonate of soda, whiting, and carbonate of lead or white lead, or other
chemical materials well known to chemists as having the property of absorbing
sulphuretted hydrogen and sulphurous acid; but we prefer those herein-before
named as being less expensive. And through the funnel X we pour in water
till it rises to the guage cock V, a little above the plate Q, R, the said
materials being in the proportion of ten to one hundred of water.
fill the vessels b and c nearly full of distilled water; into the vessel b
we place about fifty pounds of litharge, massicott, or protoxide of lead, to
this we add twenty pounds of commercial nitrate of lead, or such quantity
that the nitrate of lead is in weight about one sixteenth the weight of
We

page_text: the water in the vessel. We then turn the steam into the steam jackets through
the pipe, which leads from an ordinary steam boiler, making the liquid in the
vessels b and c to boil. We then set the stirrer k, k, k, in motion by a strap
from a drum on a shaft, and passing on a pulley attached to the shaft of the
stirrer at, but not shewn in the Drawing. The piston rods of the pumps/
and mare severally attached to two cranks upon a shaft, which make thirteen
revolutions per minute, so that the pump will draw the liquid from the
vessel band discharge it into the filter s, whence, passing through that filter,
it descends into the open vessel c, whilst the pump / draws the liquor, and
necessarily some white lead with it, from the vessel c, and discharges it into
the filter 7, when the liquor passes through that filter and falls into the open
vessel b. In this condition of things, the air which is taken into the bellows
passes part through the furnace and part through the flame chamber, and
thence through the washing vessel and through the pipe a into the coil i,i, i,i,
whence it escapes in the form of carbonic acid gas, together with the other
portions of the atmospheric air and gases, through the small holes made in
that coil, and will be found to rise up through the liquid in the vessel c in a
great number of buffles; and the apparatus being now in the process of
making white lead, that substance will be found to be pumped up out of the
vessel c with the liquor and thrown into the filter r, where the white lead will
be arrested whilst the liquor filters through into the vessel b; at the same time
a small quantity of litharge and impurities will be found to be collected in the
filters. The filter r, which contains the white lead, is removed or exchanged
for another as often as it becomes filled with white lead, and the filters is also
exchanged when the pores of the filter become filled with litharge and
impurities. The furnace F will require to be filled about three times in
twenty-four hours when in constant action. The agitator in the washing
vessel is kept slowly in motion by a pulley on the shaft Y, not shewn in the
Drawing. From time to time it is necessary to add fresh litharge into the
vessel b, taking care not to allow the vessel 6 either to get empty of litharge,
or so much to accumulate as to overload the agitator k, k, k. Occasionally
fresh water must be poured into the funnel X, whence, passing through
the cock, it enters the washing vessel P, so that the liquor in this vessel shall
never be found much below the guage cock V in the process of working.
After a long time the materiais placed in this vessel P, with the accumulations
of solid matter, require to be drawn out through the cock W, and fresh
materials and water put in as at first. It will be proper from time to
time to examine the liquor in the vessels b and c,-to-ascertain--if-by-any
waste, leakages, or otherwise this liquor has become too weak, or contains

page_text: too little of the nitrate of lead. The test for keeping this liquor at the
right strength will be found by taking out a little liquid from the vessel b
whilst it is boiling hot, and setting it aside and allowing it to cool, when
a crystallization or precipitation ought to be produced of basic nitrate of lead.
If it should be found that there is no appearance of such crystals, this will
indicate that by some means the liquor has become too weak, and that some
fresh nitrate of lend must be added. By testing after this manner the hot
liquor taken out and allowed to cool soon after the vessels b and c were first
charged, the operator will be enabled to ascertain by comparison when the
working liquor is at the proper strength.
We have thus described the apparatus we use so far as is necessary for the
producing of carbonate of lead according to our Invention, and we now
proceed to describe the apparatus and means used for giving this white lead a
body best adapted for commercial purposes, and at the same time preventing
any sensible loss or waste of the solution of nitrate of lead, which otherwise
might be carried off with the white lead taken from the filter. By referring
to Figure 5 we have a stand A, A, A, A, into which we place a square
box B, B, B, B, open at the top, across the bottom of which box there is
drawn a coarse linen cloth or sheeting as a filter. The contents of the before-
mentioned filter r is removed and put into the box B, B, B, B, which we may
suppose to fill the box up to C. On this white lead we pour pure water to
wash out the solution of nitrate of lead remaining mixed with the white lead.
This process of pouring on water we repeat until the wash water which filters
through the white lead and drops from the filtering cloth is so free from the
solution of nitrate of lead that a portion caught in a glass and poured into a
solution of carbonate of soda will not render that solution opake or milky.
The accumulations of this wash water fall into the tub D, D, D, D, where it
is collected, and from time to time returned to the litharge vessel b, Figure 1,
so that not any of the wash water containing the solution of nitrate of lead
shall be lost; which likewise may be so arranged that the vessels b and c shall
be thus supplied to compensate the loss of water by evaporation. The washed
white lead from the vessel B, B, B, B, is now removed to the tub E, E, E, E,
Figure 6, which we call the mashing tub, in which there is an upright shaft
inade of gun metal F, F, with arms G, G, G, these arms being slightly
inclined so as to cut through the white lead, and to create a tendency to press
it towards the bottom as the arms revolve, thus continually mashing the white
lead, which brings the particles nearer together, while the water held therein
is allowed to separate from the white lead through the bottom II, H, which is
full of holes, over which a filtering cloth is drawn, thus permitting the water

page_text: which is liberated from the white lead by the process of mashing to fall into
the vacant space H, E, where it accumulates, and may be drawn off by the
cock I when required. The process of mashing is continued until water
ceases to drip from the white lead, after which this mashed white lead
is allowed to pass through the channel K into the hopper L of the hori-
zontal grinding mill, Figure 7, and thence (being ground) it passes into the
vessel M, M. This lead, if required for immediate use, may be compressed
by any convenient mode, by which a portion of the remaining water may
be pressed out, and it may then be removed and dried by any of the usual and
well known modes practised by white lead manufactures. Now whereas we
do not claim as our Invention, or as any part thereof, any particular apparatus
for generating carbonic acid gas, nor the particular means herein-before
described of introducing the same when generated into our solution, although
we have shown the best which we are at present acquainted with for the
purpose of obtaining those two objects; nor do we claim as our Invention, or as
any part thereof,any particular apparatus as necessary to be used in order to
obtain either-the combustion or purification aforesaid of the vapours and gases
arising from the fuel in the furnace. But we claim as our Invention,-
First, the acting upon the vapours and gases arising from the fuel used
in the furnace employed in the process of making white lead in such manner
(by burning and by washing the said vapours and gases in manner herein-
before described), whereby we destroy the impurities in the said vapours and
gases which are injurious to the colour and quality of white lead, and are
enabled to use that cheap kind of fuel called anthracite or stone coal, or
mineral coal, or coke in the said furnace instead of charcoal, and also to use
the carbonic acid gas obtained therefrom in the process of manufacturing
white lead.
Secondly, the manufacturing of white lead from compounds of nitric acid
with oxide of lead, in which the quantity of oxide of lead bears a greater ratio
to the nitric acid combined therewith than the oxide of lead bears to the nitric
acid in the ordinary nitrate of lead of commerce, and which nitrates we call
and are known by the name of basic nitrates of lead. And,
Thirdly, the making of white lead by uniting and acting upon or mixing
litharge,massicott,or protoxide of lead with nitrate of lead (which uniting and
acting upon or mixing are best effected by boiling, as herein-before described,
but may be obtained, though not so advantageously, without boiling), and
submitting the same so mixed together to the action of or bringing the same
so mixed together minutely into contact with carbonic acid in order to produce
carbonate of lead, or as it is usually called white lead,and in such manner that

page_text: the same nitrate of lead may be used over and over again many times with
fresh portions of litharge, massicott, or protoxide of lead, as herein-before
described.
And such our Inventi on being, to the best of our knowledge and belief,
entirely new, and never before used within that part of Her said Majesty's
United Kingdom of Great Britain and Ireland called England, Her 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
disguise, 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 our said Invention.
.In witness whereof, we, the said Charles Button and Harrison Grey
Dyar, have hereunto set our hands and seals, the Twenty-second
day of June, in the year of our Lord One thousand eight hundred
and thirty-eight.
CHA (L.S.) BUTTON. 1
HARRISON GREY (L.s.) DYAR.
AND BE IT REMEMBERED, that on the Twenty-second day of June,
in the year of our Lord 1838, the aforesaid Charles Button and Harrison
Grey Dyar came before our said Lady the Queen in Her Chancery, and
acknowledged the Specification aforesaid, and all and every thing thercin
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-third day of June, in the year of our Lord One