CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF SOAP
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
LAMBERT, of No. 12, Coventry Street, in the Parish of Saint James, within
the Liberty of the City of Westminster, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria did, by Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Fifteenth day of July, in the fourth year of Her reign, give and grant
unto me, my executors, administrators and assigns, Her especial licence,
full power, sole privilege and authority, that I, the said John Lambert,
my executors, administrators, and assigns, and every of them, during the term
of years therein expressed, should and lawfully might make, use, exercise,
and vend, within that part of the United Kingdom of Great Britain and
Ireland called England, Her Dominion of Wales, and the Town of Berwick-
upon-Tweed, and also in all Her Majesty's Colonies and Plantations abroad,
the Invention of "CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF SOAP" (com-
municated to me by a certain person residing abroad); in which said Letters
Patent is contained a proviso that if I, the said John Lambert, should
not particularly describe and ascertain the nature of the 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 Her Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said Letters Patent, then that all liberties and advantages
whatsoever thereby granted should utterly cease, determine, and become void,

page_text: as in and by the same Letters Patent, relation being thereunto had, will more
fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Lambert, do by this instrument in writing under my hand and seal
declare that the said Invention and improvements, in respect of which 1
claim the benefit of the said Letters Patent, consist in using bones (or the
horns and hoofs of animals) in the manufacture of soap, and that my method
of using bones in the manufacture of soap is as follows:-
In the first place I clean the bones by washing them, which I do either with
hot water, or (by preference) with a weak mixture of sulphuric acid and water,
but I do not claim the benefit of these Letters Patent for these or any methods
of cleaning the bones. I then reduce the bones by caustic alkaline ley or
lees to a soft substance, resembling and of about the same consistency with
the fat or grease procured from kitchens by soap boilers, and known to them
by the name of kitchen stuff. This reduction I effect as follows:-The bones
should, before or after they are washed, be broken into very small pieces, and
the pieces put into a vessel capable of containing caustic alkaline lees, and the
bones are to be shaken or rammed down to the bottom of the vessel, so as to
lie in as small a space as possible. The caustic alkaline lces are then to be
poured upon the bones till they are completely covered. I prefer using the
caustic alkaline ley or lees of crystals of soda, and I find it most expedient to
use them of about the specific gravity of from 1.120 to 1140, the specific
gravity of distilled water being taken at 1.000. The bones are left covered
with the caustic alkaline lees before described until they are reduced to
the soft substance above mentioned, which will take place in about a fort-
night or three weeks. If the caustic alkaline lees be weaker than as above
described the time will be longer; if they are much stronger the product is
liable to become too caustic. If the bones are not broken into small pieces
before the caustic alkaline lees are applied the process will apply but imper-
fectly, because more lees will be requisite, in order that the bones may be
covered, and then the bones will be reduced to too thin a matter, and a longer
time will be requisite for this part of the process. It is expedient that the
bones should not be broken down into a powder, but short of this, the smaller
the pieces the better. The soft substance obtained as above is then ready for
the next process. The bones may also be prepared for the next process by
boiling them (when cleaned and broken into small pieces, as above described)
with the lees before described, in a close boiler carrying the temperature to
from 250° to 260° of Fahrenheit, and keeping up the temperature for about

page_text: ten or twelve hours; but if the bones used are of great hardness, or if they are
not sufficiently broken, a longer time will be required for the boiling. A
cylindrical boiler, on the principle of the common steam boiler, fixed on the fire
with the end downwards will be found convenient, and it should have in addi-
tion to the ordinary fittings up and structure a man-hole at the top for putting
the materials into the boiler, and another only man-hole about two feet above
the bottom for taking the materials out of the boiler, and a discharge cock at
the bottom for drawing off the liquid contents, a mercury chamber for a ther-
mometer to shew the temperature, and a safety valve. After the bones have
been kept at the temperature above mentioned for the time above mentioned
they are to be taken out and well pounded or crushed; they are then ready
for the next process. I do not claim the benefit of these Letters Patent for
the structure or fittings of this boiler. Of the two methods above described
of preparing the bones for the next process, I prefer the former. The next
process is to grind the substance (whether prepared by the first or by the
second method, into a paste. The grinding is effected by passing the substance
between a pair of cylindrical rollers two or three times, screwing the rollers
close at each passing. The cylindrical rollers may be arranged and constructed
according to any of the methods used for applying cylindrical rollers to pro-
duce pressure, for instance, as in the mills used by grocers for muscovado
sugars, but the rollers should be so constructed and arranged that the surface
of one of the pair moves faster than the surface of the other of the same pair,
in order that there may be friction produced as well as pressure.
The same
process may be still more conveniently effected by using three pair of rollers
mounted in a frame above each other, so placed that the substance after being
ground by the top pair falls between the second pair, which are closer set, and
after passing between this second pair falls between and is again ground by
the bottom pair of rollers, which are closer set than the second, one power
driving the whole three pair of cylinders. These pairs of rollers must be each
fitted with a hopper; their size must depend on the quantity of substance
intended to be operated on. A pair of rollers, fifteen inches long and six
inches diameter, worked by manual labour, will grind from two to three hun-
dredweight per twelve hours. I do not claim the benefit of these Letters
Patent for the cylindrical rollers or hoppers, nor for any mode of arrangement
by which they may be used; and I declare that any other mode of grinding
the above-mentioned substance to an uniform consistency may be used, though
the above described is the best with which I am acquainted. The result of
this process will be a paste. The next process is to mix the paste when thus
prepared and ground with soap made in the ordinary manner while hot and in

page_text: a state for framing. The paste previously to being mixed is to be heated in
any convenient vessel, and it will be found most convenient to apply steam for
the heating; but I do not claim the benefit of these Letters Patent for the
application of steam rather than any other method of heating the paste. The
heating of the paste is to be carried near but not up to the boiling point. If
the pasto be found so thick that the heat will not readily render it fluid, or if
after it has become fluid, it is found to be much thicker than the hot soap
with which it is to be mixed, in either case caustic alkaline ley or lees (such
as before described); or if the paste be too caustic, water should be added in
sufficient quantity to bring the paste under the operation of the heat to as
nearly as possible the same consistency as the soap with which it is to be
mixed. If the paste after it has become fluid by the heat be much thinner
than the hot soap, the heating is to be continued till the evaporation has
brought the paste as nearly as possible to the same consistency as the hot
soap; or the same result may be produced by adding a sufficient quantity of
paste of thicker consistency. When the paste is at the heat and of the con-
sistency above described, and the soap hot and in a state fit for framing, the
two are to be mixed thoroughly either in the vessel in which the hot paste is,
or in another vessel, or they may be mixed while framing. While the paste is
being heated it must be constantly stirred to prevent burning or adhesion to
the bottom or sides of the vessel. When the paste and soap have been tho-
roughly mixed, the mixture is to be framed and treated in the ordinary
manner. The quantities of the paste and soap may be to each other in the
proportion of about two parts soap to one part paste, but these proportions may
be varied according to the quality of soap which it is wished to produce; that
is to say, if the object be to produce a cheaper soap a larger proportion of the
paste may be used, and in some cases as much as two thirds of paste to one
third of soap. The article will be improved by mixing with the ground paste,
while it is being heated, about ten pounds of tallow and ten pounds of caustic
alkaline lees (before described) to every one hundred pounds of paste, if it is
intended to produce white soap; and about three pounds of palm oil and
three pounds of caustic alkaline lees (before described) to every one hundred
pounds of paste, if it is intended to produce yellow soap. But I do not claim
the benefit of these Letters Patent for mixing the tallow or oil with the paste,
or with any of the ingredients above mentioned.
And I do further declare that the horns and hoofs of animals may also be
used in the manufacture of soap (though in my opinion less advantageously than
bones); and my method of using horns and hoofs in the manufacture of soap is
the same as that above described for using bones, excepting that where horns or

page_text: hoofs are used instead of bones it is expedient to prepare them for the process
of grinding into paste by covering them with lecs, in the manner herein-before
described with respect to bones; and that the method above described of
preparing the bones for grinding, by boiling and crushing, cannot be so advan-
tageously applied to horns or hoofs.
And I declare that I claim the benefit of these Letters Patent for the use
of horns and hoofs, or either of them, as well as bones, in the manufacture of
soap.
And lastly, I do hereby declare that the above is a full and true account of
the nature of the said Invention and improvements, and of the manner in
which the same is to be performed.
In witness whereof, I, the said John Lambert, have hereunto set my
hand and seal, this Fifteenth day of January, One thousand eight