IMPROVEMENTS IN THE MANUFACTURE OF SOAP
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by William Sterling Jackson at the
Office of the Commissioners of Patents, with his Petition, on the 2nd
May 1860.
I, WILLIAM STERLING JACKSON, of Milton Street, Dorset Square, in the
County of Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF SOAP," to be as follows:—
This Invention relates to an improved method of introducing into ordinary
soaps the salts of soda, potash, barytes, alumina, and lime, generally, but more
especially the sulphates and carbonates of such salts, and consists,-
Firstly, in intimately combining (by boiling or agitation, or both) the above-
mentioned salts, (either in their dry and powdered state or dissolved in steam
or water in the state of crystals, or in the state of crystals melted in their water
of crystallization,) with saponified fluid rosin, such saponified rosin containing a
small amount of moisture, and prepared in a manner herein-after described.
And, secondly, in mixing this salinated and saponified rosin with the ordi-
nary potash and soda soaps in their finished and fluid state, either in the pan,
frames, or any intermediate or other vessel. This previous intimate union of
the salts with the rosin produces much greater firmness and durability in the
resulting soaps, by preventing that tendancy to separate and crystallize which.

page_text: such salts when mixed with soaps by the old method invariably possess, namely,
the mixing of the salts directly with the soap. For the purposes of this Inven-
tion I propose to employ a circular open iron pan (capable of containing 500
or 600 gallons, and, by preference, of slightly greater depth than the diameter)
set in brickwork in the usual manner, and having a fire-grate beneath for the
purpose of applying external heat to the bottom of the pan. The pan is fitted
with a metal pipe and perforated coil for the admission of free steam for boiling
or heating the contents thereof. The pan is also fitted with a vertical revolving
metal shaft, to which are attached one or more rows of horizontal bars, to be
employed for the purpose of mixing the contents of the pan.
Into the pan above described I place 10 hundredweigt of rosin, broken into
When the
small pieces, and melt the same by the external action of heat.
rosin becomes fluid and attains the heat of about 230° Fahrenheit, I draw the
fire or moderate its effects by means of a damper; I then take 30 gallons of
caustic soda ley (if for a hard or soda soap or potash ley, it for a soft or potash
soap), previously reduced by concentration to specific gravity 1-40, and contain-
ing about twenty-eight per cent. of caustic alkali, and at boiling heat; add
gradually this ley to the fluid rosin. Should carbonate of soda be employed
instead of caustic soda to saponify the rosin, I prefer to use the soda crystals
of commerce, such crystals being previously melted in their water of crystal.
ization.
I would state, that although the above proportions of alkaline ley and rosin
(viz., 3 gallons of ley to one hundredweight of rosin) will, in practice, gene-
rally be found to produce the best results, I do not confine myself strictly to
those proportions; thus the proportions of ley to the one hundredweight of
rosin may be reduced, or in some instances increased to 4 or even 6 gallons,
without materially impairing the quality of the resulting compound. Imme-
diately after the chemical union between the rosin and alkali is completed, I
take, say, 300 pounds weight sulphat of soda, 700 pounds of carbonate of
soda, 84 pounds of carbonate of lime or sulphate of barytes, 30 pounds of car-
bonate of potash, and 30 pounds of sulphate of alumina, all previously melted
together in their water of crystallization, and place them in the pan containing
the saponified rosin, and then proceed to intimately mix the saponified rosin
with the above-mentioned salts by the admission thereof through the before-
mentioned pipe and perforated coil of high-pressure steam (say, about 30.
pounds to the inch), and by setting in motion the vertical shaft and continuing
the action of the steam and agitation until the materials assume a perfectly
homogeneous and snooth appearance. This salinated and saponified rosin after

page_text: having cooled down to about 150° Fahrenheit, is to be introduced into the ordi-
nary soda and potash soaps in their finished and fluid state (in the proportion
of from 5 hundredweight to the ton to 10 hundredweight to the ton), and the
whole thoroughly mixed together (by hand labour or by steam power) either in
the pan, frames, or any intermediate or other vessel.