IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD, AND PRODUCTION OF CARBONIC ACID GAS FOR THE SAID MANUFACTURE AND FOR OTHER USEFUL PURPOSES
Year: 1868

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD, AND
PRODUCTION OF CARBONIC ACID GAS FOR THE SAID MANUFACTURE AND FOR
OTHER USEFUL PURPOSES."-A communication from abroad by Henry
Hannen, Benjamin Franklin Pine, and Thomas Woods, all of
Philadelphia, State of Pennsylvania, United States of America.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 30th September 1868.
I, J IN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF WHITE LEAD, AND IN
THE PRODUCTION OF CARBONIC ACID GAS FOR THE SAID MANUFACTURE AND FOR
OTHER USEFUL PURPOSES," a communication to me from abroad by Henry
Hannen, Benjamin Franklin Pine, and Thomas Woods, all of Philadelphia,
State of Pennsylvania, United States of America, to be as follows:-
PS11

page_text: The first part of this Invention consists in subjecting metallic lead
to the action of carbonic acid gas in a close chamber and then to a
spray of dilute acetic acid, the gas being at such a temperature that a
proper degree of heat is maintained within the chamber without the
use of heating apparatus, the metallic lead during its process of con- 5
version into a carbonate being subjected to solutions of chloride of soda
and carbonate of soda while in the same chamber, which is lined with
slate, glass, or other material capable of resisting the action of the
acids. It is further proposed to use in conjunction with the said
chamber a jet or jets of steam for the purpose of imparting heat and
moisture thereto when required.
The object of this part of the Invention is to produce a chemically
true carbonate of lead of a greater density, purity, and whiteness, and
at less expense than the ordinary white lead of commerce, which is in
reality a hydrate of the oxide of lead with a small portion of carbonic 1
acid; this result is mainly attained by an excess of carbonic acid gas
which could not be obtained by the usual process of white lead
manufacture.
The second part of this Invention consists in the application of
the above improvements, in whole or in part, to the Dutch process of
manufacturing white lead, by injecting into the spaces within the beds
occupied by the pots steam, carbonic acid gas, and if necessary the spray
or vapour of dilute acetic acid.
The third part of this Invention consists in the mode or process
described hereafter of producing from the waste products of combustion
a pure carbonic acid gas for the manufacture of white lead and for other
useful purposes.
In carrying out this part of the said Invention the following arrange-
ments of apparatus or its equivalent may be employed :-It consists of a
chimney or fire-place provided with a sliding damper, below which is a
pipe forming a communication between the chimney and a reservoir, the
said pipe being furnished with a throttle valve. The contents of the said
chamber are withdrawn by a fan and forced through a pipe into a closed
vessel the said pipe extending nearly to the bottom of such vessel and
having a number of small lateral perforations made therein. Water im-
pregnated with chlorine is introduced into the said vessel through a funnel
and feed pipe in such quantities that there shall be within the vessel a
space above the liquid for the accumulation of carbonic acid gas under

page_text: pressure caused by the action of the fan. This gas is discharged and
distributed through a pipe for that purpose to white lead making or
other apparatus in which a pure carbonio acid gas is available for any
manufacturing purposes. A try cock is used for determining the height
of the chlorinated water in the vessel, and a cock is provided through
which the contents of the vessel may be discharged. In using the
above-described apparatus the throttle valve is closed, and the damper
in the chimney permitted to remain open until the fuel in the furnace
or fire-place is thoroughly ignited, when the damper is closed, the
throttle valve opened, and the fan set in motion. The unconsumed
gaseous products of combustion accelerated by the exhaustive power
of the fan will rush first into the closed chamber or reservoir, where
particles of dust and refuse matter are deposited owing to a screen of
perforated plate or wire gauze at the entrance of the pipe leading into
such closed chamber; after passing through this screen the gas is forced
through the pipe leading to the chlorinated water in the said vessel,
which water it permeates and by which the gas is purified and con-
verted into a pure carbonic acid gas available for the manufacture of
white lead and for other useful purposes. The purified gas accumulates
under pressure caused by the fan in the said vessel, from which it is
consequently forcibly ejected through the distributing pipo.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 30th March 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Jonn
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Mid-
dlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of September, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special license
that I, the said John Henry Johnson, my my executors, administrators,
and assigns, or such others as I, the said John Henry Johnson, my
executors, administrators, or assigns, should at any time agree with,

page_text: USEFUL
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "Im-
PROVEMENTS IN THE MANUFACTURE OF WHITE LEAD, AND IN THE PRODUCTION OF
CARBONIC ACID GAS FOR THE SAID MANUFACTURE AND FOR OTHER
PURPOSES," a communication from abroad by Henry Hannen, Benjamin
Franklin Pine, and Thomas Woods, all of Philadelphia, State of
Pennsylvania, United States of America, upon the condition (amongst
others) that I, the said John Henry Johnson, ny executors or adminis-
trators, by an instrument in writing under hand and seal, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accom-
panying Drawings, and to the letters and figures marked thereon, that
is to say):
-:
The first part of the said Invention consists in subjecting metallic
lead to the action of carbonic acid gas in a close chamber and then to
a spray of dilute acetic acid, the gas being at such a temperature that
a proper degree of heat is maintained within the chamber without the
use of heating apparatus, the metallic lead, during its process of con-
version into a carbonate being subjected to solutions of chloride of soda
and carbonate of soda while in the same chamber, which is lined with
slate, glass, or other material capable of resisting the action of the
acids. It is further proposed to use in conjunction with the said chamber
a jet or jets of steam for the purpose of imparting heat and moisture
thereto when required.
The object of this part of the Invention is to produce a chemically
true carbonate of lead of a greater density, purity, and whiteness, and
at less expense than the ordinary white lead of commerce, which is in
reality a hydrate of the oxide of lead with a small portion of carbonic
acid. This result is mainly attained by an excess of carbonic acid gas,

page_text: which could not be obtained by the usual process of white lead
manufacture.
:
'
The second part of this Invention consists in the application in the
manner described hereafter of the above improvements, in whole or in
part to the Dutch process of manufacturing white lead by injecting
into the spaces within the beds occupied by the pots steam, carbonic acid
gas, and if necessary the spray or vapour of dilute acetic acid.
ر
The third part of this Invention consists in the mode or process
described hereafter of producing from the waste products of combustion
a pure carbonic acid gas for the manufacture of white lead and for other
useful purposes.
And in order that the said Invention may be fully understood, I
shall now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed Sheet of
Drawings, the same letters of reference indicating corresponding parts in
all the corresponding Figures.
In reference to the first part of the Invention, Figure 1 is a front
elevation of an apparatus which may be used for carrying out the im-
provements in the manufacture of carbonate of lead, and Figure 2.is
a sectional elevation.
A, A, are the walls; C. is the top and B the bottom of a case or
chamber, at one side of which is a door D equal in height to that
of the chamber, and on the said door are openings a, to each of which
is fitted a smaller door or cover 6 hinged to the main door. The interior
of the case as well as the inner sides of the door D and covers. b, b,
are lined with slate, or glass, or other material which will not be affected
by the acid introduced into the chamber, and across the latter extend
a series of perforated plates s, s, or their equivalents. With the lower
part of the chamber and at one side of the same, and with a reservoir
containing pure carbonic acid gas under pressure, communicates a pipe E
and at the opposite side of the chamber near the top is an opening e
to which is fitted a valve or damper. Metallic lead in the form of
scraps or. flakes is placed upon the plates s, s, and is sprinkled with a
liquor consisting of acetic acid and water in the proportion of one
gallon of acetic acid to about eight of water, the acid in the liquor
combining with the lead and producing sub-acetate of lead.
The
chamber is now closed, and carbonic acid gas under pressure and at
a temperature of from 100° to 120° Fahrenheit is passed through the

page_text: tube E into the chamber, where it combines with the sub-acetate of lead
producing carbonate of lead. At any time during the above-described
operation when the acetate is in excess a solution of chloride of soda
is sprinkled over the lead, and after this the lead is sprinkled with a
solution of carbonate of sodda of strength sufficient to neutralize the
acetate, care being taken to so proportion the quantity of soda that no
excess of the same way remain with the lead to saponify the oil with
which the carbonate of lead is afterwards ground. When the outer
surface of the lead has become thoroughly carbonized it is again
sprinkled with a mixture of water and acetic acid containing a greater
proportion of acid than the liquor first employed; after which the
solutions of soda are thrown on to the lead as before, the said solutions
aiding in the carbonizing of the lead, and also improving the quality
of the product. The different liquors thrown on to the lead should not
be of a lower temperature than 120° Fahrenheit, and they may be readily
deposited on the lead from a pipe terminating in a rose which is intro-
duced into the chamber through the doorway or through suitable openings
in the same to which doors are adapted. The carbonic acid gas may
be heated prior to its introduction into the chamber by a jet of steam,
although the plan of producing a pure carbonic acid gas in a heated state
in a manner hereafter described, and which forms the third part of this
Invention is to be preferred. By thus introducing the gas in a heated
state into the chamber it will be brought into much more intimate contact
with the lead than if it was introduced cold into a heated chamber,
at the top of which it would collect, while the use of heating apparatus,
which render the chamber difficult to clean is avoided. It will also
be seen that the proper cleansing of the chamber is insured by lining
the same with slate or its equivalent, and that the waste of material
and injury to the quality of the product resulting from the walls of
the chamber absorbing the materials introduced into the same is avoided.
After the metallic lead has been thus converted into a carbonate it
may be removed from the perforated plates through the doors of the
chamber, or what is preferable slats capable of being tilted may be
substituted for the perforated plates, so that the carbonate of lead may
be precipitated on to the floor of the chamber from whence it may be
removed. There should be in the top of the chamber small vent holes
which may be opened and closed at pleasure.

page_text: and 4, consists in the application of part of the above improvements
to the well-known Dutch process of manufacturing white lead.
Figure 3 represents a vertical section of part of a Dutch bed, and
Figure 4 a sectional plan of Figure 3. A, A, represent the wooden
walls which enclose the bed; on the ground B is deposited a mass C
cf spent tan or manure to the depth of about eighteen inches, on this
are placed in rows a number of pots D containing a supply of vinegar a,
above which and within the pots are coiled sheets of lead or lead
in other suitable forms. Above the first layer of pots are laid boards e,
and above the latter another stratum of spent tan or manure about one
foot deep is deposited, and on this is placed another layer of pots, and
this is continued to any desired height. This Dutch process is well
known to be one of a very precarious character owing to the fermentation
being liable to interruptions from a variety of sources, and when fermen-
tation is arrested the process of conversion of metallic into white lead
ceases, and the destruction and rebuilding of the bed is rendered
necessary. In order to obviate these evils it is proposed to introduce
into each space occupied by a layer of pots steam through a pipe F,
this steam at once surrounding the pots, warming the same, and promoting
fermentation When warmed to the proper temperature the supply of
steam is cut off and through another pipe or pipes E into the same
space occupied by the pots is introduced pure carbonic acid gas under
pressure. This gas gains access to the lead and has the same good
effect in producing a pure carbonate of lead as it has in the process
described on reference to the first part of the Invention. Should it
be found on practising this process that a supply of acetic acid is
necessary, spray or vapor of vinegar may be introduced from time to
time through other pipes to the spaces containing the pots. It will
be best to have in connection with the bed a central vertical pipe
communicating with the different spaces containing the pots, so as to
form a vent for the escape of superfluous steam, gas, or vapour. If
necessary air may be admitted in limited quantities to the spaces
containing the pots.
The mode or process of producing from the waste products of com-
bustion a pure carbonic acid gas is illustrated in Figures 5 and 6, in
which A represents part of a chimney of any furnace or fire-place,
and a a sliding damper, below which is a pipe b forming a communication
between the chimney and the reservoir B, the said pipe being furnished

page_text: with a valve e. D is a fan by means of which the contents of the
chamber are withdrawn through the pipe d and forced through the
pipe into the closed vessel E, the pipe f extending nearly to the
bottom of the vessel and having a number of small lateral perforations.
Water impregnated with chlorine is introduced into the vessel E through
the funnel F and pipe G in such quantities that there shall be within
the vessel a space m for the accumulation of carbonic acid gas under
pressure caused by the action of the fan. This gas is discharged and
distributed through the pipe K to white lead making or other apparatus
in which a pure carbonic acid gas is available for any manufacturing
purposes. L is a try cock used for determining the height of the
chlorinated water in the vessel E, and M. a cock through which the
contents of the vessel may be discharged. In using the above described
apparatus the valve e is closed and the damper a permitted to remain
open until the fuel in the furnace or fire-place is thoroughly ignited
when the damper a is closed, the valve e opened, and the fan d set
in motion. The unconsumed gaseous products of combustion accelerated
by the exhaustive power of the fan will rush first into the reservoir B
where particles of dust and refuse matter are deposited owing to a
screen h of perforated plate or wire gauze, at the entrance of the pipe d
after passing through which the gas is forced through the pipe f and
through the chlorinated water in the vessel E, by which the gas is
purified and converted into a pure carbonic acid gas available for the
manufacture of white lead and for other useful purposes. The purified
gas accumulates under pressure caused by the fan D in the vessel E from
which it is consequently forcibly ejected through the distributing pipe K.
It will be understood that although specific apparatus has been
described for carrying out this part of the said Invention, the same
may be altered and modified and other apparatus substituted for that
explained and illustrated in the Drawing, and the same remarks will
apply to the first and second parts of the said Invention.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,-
First. Subjecting metallic lead to the action of carbonic acid gas,
substantially as and for the purpose herein set forth.

page_text: Second. Subjecting metallic lead deposited on perforated plates or
their equivalents in a close chamber to a spray of dilute acetic acid,
substantially as described for the purpose specified.
Third. Subjecting metallic lead after its treatment with dilute acetic
acid in a close chamber to the action of carbonic acid gas introduced into
the said chamber at such a temperature that a proper degree of heat
is maintained within the same without the use of heating apparatus.
Fourth. Subjecting metallic lead during its process of conversion into
carbonate of lead to the actions of solutions of chloride of soda and
carbonate of soda, substantially as and for the purpose described.
Fifth. Lining the interior of the aforesaid chamber with slate, glass,
or other material which will resist the action of the acid and prevent
the absorbtion of the same by the walls of the chamber.
Sixth. The employment in combination with the said chamber of
a jet or jets of steam for imparting heat and moisture to the same when
required.
Seventh. The application of the above-mentioned improvements in
whole or in part to the Dutch process of manufacturing white lead by
injecting into the spaces within the beds occupied by the pots steam,
carbonic acid gas, and if necessary the spray or vapor of dilute acetic
acid as herein set forth.
Eighth. The production from the waste products of combustion of
a pure carbonic acid gas for the manufacture of white lead and for other
useful purposes.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Thirtieth day of
March One thousand eight hundred and sixty-nine.
J. HENRY JOHNSON. (L.D.)