IMPROVEMENTS IN THE MANUFACTURE OF SOAP AND WASHING PASTE, AND OF THE MATERIALS USED THEREIN
Year: 1853

page_text: LETTERS PATENT to l'ierre Auguste Tourniere, of Lawrie Terrace,
St. George's Road, in the County of Surrey, Gentleman, and
Louis Nicolas De Meckenheim, of Birmingham, in the County of
Warwick, Gentleman, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF SOAP AND WASHING PASTE, AND OF THE MATERIALS
USED THEREIN."
Sealed the 9th January 1854, and dated the 9th July 1853.
PROVISIONAL SPECIFICATION left by the said Pierre Auguste
Tourniere and Louis Nicolas De Meckenheim at the Office of
the Commissioners of Patents, with their Petition, on the 9th July
1853.
WC, l'IERRE AUGUSTE TOURNIERE, of Lawrie Terrace, St. George's
Road, in the County of Surrey, Gentleman, and LOUIS NICOLAS DE
MECKENHEIM, of Birmingham, in the County of Warwick, Gentleman,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF SOAP AND WASHING PASTE, AND OF THE MATERIALS
USED THEREIN," to be as follows:-
This Invention consists, in the first place, in manufacturing soap
with the aid of a concentrated solution of caustic alkali of a degree of

page_text: strength sufficient to produce the neutralisation or saponification of
oils and fatty bodies. A simple lye or alcaline solution of a strength
not greater than twenty-four degrees of Cartier's areonicter is first
obtained in the following manner-To one hundred parts of water are
added fifty parts in weight of pulverised soda, which is well mixed up
and boiled for about half an hour; the boiling is then suspended, and
twenty-five parts in weight of pulverised quick lime are added, and the
boiling renewed and continued for about two hours; care being taken
to stir up the mixture well at intervals, and to add water to supply the
quantity carried off by evaporation, the level being always kept at least
half a foot above the lime. The mixture is after this allowed to
rest for a certain time, not exceeding twenty-four hours, when the
lime should be precipitated to the bottom, and the liquid quite clear
above.
This liquid is then drawn off' by a siphon or other convenient means,
so that the lime be not again stirred up and mixed with it. The lye
thus obtained should be of about eighteen degrees to twenty-four
degrees of Cartier's arcometer, according to the quantity of liquid
remaining in the boiler.
This is placed in a close vessel, and fresh water, hot or cold, is added
to the lime, which is then stirred up and afterwards allowed to settle,
when the supernatant liquid is drawn off' and put into a close vessel.
This is repeated until all the strength is taken out of the lime, which
is then thrown away, or it may be sold for manure.
Each succeeding lye is, of course, of a less strength, that is, is less
saturated with caustic soda.
These solutions are afterwards concentrated to about thirty-seven
or thirty-eight degrees by boiling together, and the concentrated lyc
thereby obtained is termed "spirit of soda." This lye is employed for
hard soap; but for soft soap I use potash instead of soda, but the
operations therewith are precisely the same. With regard to the appa-
ratus employed, the mixture may be heated in a common boiler exposed
directly to the flames, or, as is preferable, by steam, the steam being
either introduced into the liquid and allowed to mix with it, thus supply-
ing what is carried off by evaporation, or is simply passed through it in

page_text: process.
The manufacture of soap by means of the concentrated lye consists
in producing a perfect mixture of it with the oil or fatty body employed,
and, as is well known, many combinations of such ingredients may be
formed.
The Invention consists, in the second place, in manufacturing soap
from ingredients and by methods hitherto unused for that purpose.
These ingredients are the entrails of animals, especially those of
sheep, instead of fat, and the meaf of oleaginous seeds or berries in
place of oil. These matters may be treated in various ways; the sapo-
nification may be brought about simply by means of the concentrated
lye; or a preliminary process may be adopted in which lime or sul-
phuric acid is used. Thus, the entrails being chopped up as small as
possible, twelve to twenty per cent. of pulverized quick lime is added
to them, and they are allowed to lic for several days; after which the
mixture is placed in a boiler, and a sufficient quantity of the caustic lye
of about twenty-four to thirty degrees added, and the whole boiled for
some hours. In this way the saponification is effected whilst the
materials are heated, but it may also be brought about without heat
by the aid of the concentrated lyc, the mixture being allowed to rest
several days until a perfect neutralisation takes place. Instead of the
lime a bath of sulphuric acid diluted in four to six times its weight of
water may be used, the remaining part of the process being the same.
Another method consists in mixing with the animal matter the
relative quantities of soda and lime, and then reducing the mass,
mechanically or otherwise, by pulverising and dividing until a perfect
mixture is obtained. The mass is theu allowed to lie in a warm place
for several days, after which it is put into the boiler and concentrated
Ive added until the perfect saponification is effected.
The oleaginous meals may be treated directly with the concentrated
lyc, or they may be previously operated upon in the same manner as
the animal matters, or they may simply be boiled for a few hours in a
mixture of lime and lye or in an acidulated bath, the subsequent pro-
cesses being the same as before.

page_text: Again, the meal may be allowed to stand for several days in a
acidulated bath, and then be put into the boiler, and the relative
quantities of soda and lime added, and the process continned as before.
In all these cases various ingredients may be added, as in the ordinary
inethods of manufacture.
The quality of the soap will be much improved by adding resins and
essential oils; palm oil, for example, produces a very good effect, and
if the soap tends to harden too quickly a bath of muriatic acid diluted
in twelve times its volume of water may be employed. All essential
oils obtained by,distillation, such as those from schist, coal, wood,
turf, &c., may be used, also pure pine rosin.
With these ingredients a low temperature must be employed, other-
wise the essential oils will be lost by evaporation. The dregs of rice
and potatoes may also be used; they must first be converted into
gelatines by mixture with boiling lye of twenty-four to thirty degrees,
and then are added to the soap.
With regard to yellow or pitch resin ordinarily employed in the
manufacture of yellow soap, I operate in different ways. The resin is
first saponified by boiling in a caustic alkaline solution of twenty-four
or thirty degrees, and is afterwards concentrated to augment the degree
of causticity; it is then mixed with the soap before the other ingredients,
and whilst the latter is at the same temperature, and upon cooling the
other ingredients are finally added. If it is not necessary that these
last should be mixed cold the whole may be mixed together hot and
at one operation.
A third part of the Invention refers to the manufacture of a paste
having the qualities of a caustic lyé, and being, in fact, an inferior kind
of soap. It is capable of being crumbled or reduced to powder, or may be
formed into cakes, and is thus prepared:-In the process first described,
instead of entirely extracting the strength from the lime precipitate by
several additions of fresh water, I only change the water once, thus only
obtaining two yes of different qualities. The lime in consequence
remains saturated with a considerable quantity of soda, and is in the
form of a paste. To this is added at least half its weight of white clay
powdered or made into a paste of uniform consistency; the boiling is

page_text: continued some time, and the matters are well mixed together. Soap
or saponified matters are afterwards added, according to the quality
required, and the mixtures may be modified in many ways,
such sapo-
naceous pastes having many uses.
A fourth part of the Invention refers to the preparation of the soda
chrystals used in the manufacture of soap, as also the use of common
or sea salt. Common salt may be employed as an adulterant, or it
may be added with advantage in the process described under the second
head; its most important function, however, lies in its conversion into
salts of soda.
In the same manner sea salt or sea water may be used instead of
fresh in the preparation of the lyes; in this case soda is added to it,
and it is made to boil longer than ordinary before adding the lime.
The chloride of sodium or common salt is converted into soda
chrystals in the following manner :-A saturated solution of the salt
being obtained is boiled for a certain time, and is then decomposed by
adding sulphuric acid to it, and iron filings, or pieces of zinc. or by
means of the voltaic battery, and during the process a current of
hydrogen, either pure or more or less carbonated, or instead of hydrogen
a current of carbonic oxide, may be passed through. This is continued
for some time, and the chlorine leaves the soda aud combines with the
hydrogen or carbonic oxide, as the case may be; it is then carried off'
by the evaporation, leaving the soda precipitate at the bottom of the
vossel. By continuing the boiling the chrystals may be produced, or
as soon as there is nothing left but the soda and pure water the prepa-
ration of the caustic alkaline lyes may be proceeded with, as already
described. The decomposition of the water is not absolutely necessary,
but it shortens the process in a remarkable degree, and renders it more
perfect. The method preferred of obtaining hydrogen gas is to pass
steam through pipes heated to a red or white beat, and pitch vapour is
mixed with the steam when the hydrogen is wished to be carbonated.
The method preferred of obtaining carbonic oxide is to burn charcoal
or coke in a close furnace, the flue from which passes down and opens
into the solution to be operated upon; the small quantities of other
matters passing along with the carbonic oxide will do no injury to the

page_text: process. These two methods of producing the gases have also the
advantage of setting the solution a boiling, without additional steam
or fuel being required for that purpose as long as this part of the
onerations lasts
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Pierre Auguste Tourniere and Louis Nicolas
De Meckenheim in the Great Seal Patent Office, on the 9th
January 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we,
PIERRE AUGUSTE TOURNIERE, of Lawrie Terrace, St. George's Road, in
the County of Surrey, Gentleman, and Louis NICOLAS DE MECKEN-
HEIM, of Birmingham, in the County of Warwick, Gentleman, send
greeting.
WHEREAS Пer most Excellent Majesty Queen Victoria, by Her
Letters Patent, hearing date the Ninth day of July, in the year of
our Lord One thousand cight hundred and fifty-three, in the seventeenth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto us, the said Pierre Auguste Tourniere and Louis Nicholas
Do Meckenheim, Her special license that we, the said Pierre Auguste
Tourniere and Louis Nicolas De Meckenheim, our exccutors, admi-
nistrators, and assigns, or such others as we, the said Pierre Auguste
Tourniere and Louis Nicolas De Meckenheim, our executors, admi-
nistrators, or assigns, should at any time agree with, and no others,
from time to time and at all tinics thereafter during the term therein
expressed, should and lawfully might make, usc, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF SOAP AND WASHING PASTE, AND OF THE MATERIALS USED
THEREIN," upon the condition (amongst others) that we, the said
Pierre Auguste Tourniere and Louis Nicolas De Meckenheim, by an
instrument in writing under our hands and seals, or under the hand
and seal of one of us, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to

page_text: 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 we, the said Pierre Auguste Tourniere and
Louis Nicolas De Meckenheim, do hereby declare the nature of our
said Invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement,
that is to say:
Our said Invention consists, in the first place, of the employment of a
concentrated solution of caustic alkali of a sufficient density to effect
the neutralization and saponification of oils and fatty bodies. We shall
first proceed to describe the application of simple lyes or alkaline
solutions, not exceeding twenty-four degrees of Cartier's arcometer.
For hard soaps we employ either natural or artificial soda ash or
crystals, and carbonate of soda. But we always prefer crystals of soda,
or carbonate of soda, obtained from the chloride of sodium or common
salt, and proceed as follows:-To one hundred parts of water we add
fifty parts in weight of powdered soda, the mixture being then boiled
for about half an hour. The boiling having been suspended or not,
as the case may be, twenty-five parts in weight of powdered quick lime
are added. The boiling is then continued for about two hours, care being
taken to stir the mixture occasionally, and to add water as fast as it
evaporates, or at least so as to keep the lime covered. It is afterwards
necessary to let the solution rest for a certain time, not exceeding
twenty-four hours. It is important that the lime should be precipitated,
and that the water he left clear. The water is then drawn off by means
of a syphon or other convenient means, care being taken that it be
removed perfectly clear without any mixture of lime. This lye should
generally have a specific gravity of eighteen to twenty degrees of
Cartier's arconicter, according to the quantity of water in the boiler.
This first lye being placed in a closed vessel, one hundred parts of hot
or cold water are poured into the boiler on the lye previously acted
upon, which is satuated with soda. After having well stirred the
mixture, and allowed it to settle again for about ten or twelve hours to
precipitate the lime, the clear water is again drawn off as before. This

page_text: water or second lye is also poured into a second vessel well closed.
This operation is continued until the whole strength of the lime is
absorbed, and the water drawn off at zero. The residue of the lime
is now removed, and may be sold as manure. By these successive
operations simple lyes are produced more or less satuated with caustic
soda, which is afterwards concentrated as lierein-after described. For
the production of concentrated lyes or caustic alkaline solutions of
from thirty-seven to forty degrees by Cartier's arcometer, the following
process is adopted :-
The first lye of a gravity of from eighteen to twenty-four degrees,
which may
be reduced to fifteen degrees, but never less, has the second
or third lye added to it. It is then boiled and kept agitated to assist
evaporation. The various lyes are added at intervals, care being taken
that they are never lower than fifteen degrees; when the whole of
the lyes have been thus acted upon the evaporation is continued, until
a solution of lime is obtained of from thirty-five to thirty-six degrees
of Cartier, or of a temperature of from thirty-seven to thirty-eight
degrees; the liquod being left for about twenty-four hours is drawn
off, and a concentrated lye is obtained, which must be kept in closed
vessels until required for use. In the case of weak lyes, of from fifteen
degrees to zero, they are employed instead of water for the simple lyes.
It is this concentrated lye which we term spirits of soda or caustic
alkaline solution, of thirty-seven to forty degrees Cartier. To obtain
this solution we employ simple lyes obtained as above described, or by
any other means which will give alkaline solutions of low degrees, that
is, from fifteen degrees upwards. The process consists then in employ-
ing simple solutions, which are raised to thirty-five or forty degrees
Cartier by boiling and concentration, giving a caustic alkaline solution
sufficiently strong to neutralize the materials with which it may be
mixed, and effecting thereby a perfect saponification. For soft soft
potash is substituted for soda, but the operation is the same; and we
may observe here, that in both qualities of soap it is beneficial to add
a small amount of one or the other alkali, but not exceeding twenty-
five per cent.
As a necessary precaution in making the concentrated lyes, an iron

page_text: ladle, not tinned, should be used, having a round handle of four or five
feet in length, so as to effect evaperation at a great distance. It is
necessary, also, to protect the eyes by spectacles or wire gauze. The
face should also be covered with a mask, and the dress composed of
linen, not cotton; it is also necessary to have vineger to wash the
hands in every time the lye may come in contact with them.
In the manufacture of the simple and concentrated lyes a cast or
wrought iron boiler is employed, heated directly by the action of a
furnance; but it is found advantageous to make the concentrating
boilers less high, and to expand their area for the sake of evaporation.
There is also another mode of heating much more preferable, namely,
by the use of steam. For simple lyes the steam may be employed in
two ways, that is, the steam pipe may be either immersed in the liquid
with which the steam mixes directly; in this case the steam supplies the
place of the evaporated water. Or by another arrangement the steam
is not brought in contact with the liquid, but is introduced by a double
bottom or series of pipes in the boiler. This latter arrangement would
be necessary for the concentrated lyes. In the manufacture of the lyes
it is necessary to use only soft water, such as rain water or river water,
and not spring water. The lime should be well burnt, and white, and
as pure as possible; it should also be used freshly burnt.
The manufacture of soap by means of the solution herein-before
described is effected in the following manner:-The principle consists
in the perfect and intimate mixture of the alkaline solution with
oil or fatty matters; say, one pound of concentrated lye and two
pounds of fat. The whole, after having been well mixed and
stirred for some time, is poured into a mould, which is covered to
protect it from the action of the air, and is placed in a warm place
(more especially in the winter season), the temperature not being
lower than seventy degrees Fahrenheit, or more than one hundred
degrees Faharenheit. The fatty matters require only to be so far
heated as to reduce them to a fluid state; but it is important
not to heat them to a higher temperature than is strictly neces-
sary to effect such liquefaction, otherwise the soap will be dete-
riorated. The liquid should be poured into the moulds cold, and very
gradually, being stirred the whole time. It is in the moulds that the

page_text: After being
saponification takes place, the scap remaining therein two or three
days, but naturally longer in winter than in summer.
taken from the mould it is cut, and if it is pure, that is, composed
only of alkale and fatty matters, it will have a tendency to crumble or
break into pieces. But it is necessary to be particular in the choice
and mixture of the materials. If, for example, tallow is employed, one
part of lard may be added, or even as much as one half of the weight
in summer. It may be mixed also with oils in various proportions, but
always so as to render the paste soft, which may be effected in various
other ways. First, by resinous soaps, as I shall explain herein-after.
Second, by baths of muriatic acid diludeil with water when leaving the
mould. Third, by adulterations introduced in the soap, some of which
improve the quality of the paste.
The adulterations are effected before the soap is poured into the
moulds, care being taken to mix them well together. As much as ten
per cent. of white lime in fine dry powder may be added. White clay
is always preferable. It is not necessary to enumerate here all the
various ingredients which may be used as adulterants, as we shall
herein-after mention such ingredients as we claim as new. Before
pouring into the moulds, and when the material is beginning to thicken
or set, a certain amount of lye may be added, which should not be less
than four or five degrees Cartier. The quantity, with the adultera-
tions already mentioned, may be about ten per cent. If the soap is to
be aromatized or scented the essence is introduced at the time of
pouring into the moulds. Colors are added also at the same time,
where required. To marble the soap cinnabar or indigo may be used
for the blue, and vermillion for the red. It is necessary always to
employ mineral blue, as vegetable colors are destroyed by the alkali.
The manufacture of soap by this process, or the mixture of the matc-
rials, may be effected in a vessel with an agitator worked by suitable
mechanism. The process may be modified also in the following
manner: The simple lye is made, and without changing the water or
removing the lime the concentration is effected by one operation thus:
spirit of soda mixed with lime, a very small quantity of which may be
introduced, especially if it is new and of the first quality, or if carbo-
nates are employed instead of .crystals, the oils or fatty matters arc

page_text: then introduced, and the operation is then continued as already
described. This process is particularly applicable to the manufacture
of common soaps.
The second part of our Invention consists in the employment of
new materials for the manufacture of soap, whether such substances
are employed exclusively or mixed with those already in use. These
substances are the entrails of animals (particularly those of sheep),
which are substituted for tallow. Also the meal of oleaginous seeds as
a substitute for oils. We treat these substances in various ways; the
neutralization may be completely effected by means of the concen-
trated lye, or we effect a preliminary operation by means of lime or
sulphuric acid. The entrails are divided or cut as small as possible,
and powdered over with twelve to twenty per cent. of quick lime.
After several days this mixture is placed in a boiler, with a sufficient
quantity of concentrated caustic lye of about twenty-four or thirty
degrees Cartier. It is boiled for some hours, and fresh lyc added as
fast as it evaporates. In this way the saponification is effected by heat,
but the process may also be effected cold by using concentrated lye as
described above. In this case the substances should soak in the lye,
and remain for some days, until perfect neutralization has taken place,
after which the operation is completed by mixing other matters or by
adulterations. The second process consists in substituting for the lime
a bath of diluted sulphuric acid, containing about four to six times its
weight of water, and the process is carried on either. according to the
hot or cold process herein-before described. The third process consists
in mixing with the animal matters relative quantities of soda and lime,
and cutting and mixing the whole well together by mechanical or other
incans, after which the mixture is covered up and placed in a warm
place for some days, when it is put in a boiler with concentrated lye,
the soap being completed in the ordinary manner, either by adding
other matters or by adulterating.
.
Oleaginous flour may be treated directly by the concentrated lye,
but it is better to cause it to undergo some preliminary operations,
which may or may not differ from those described above in reference
to fatty matters. They may be boiled for some hours, either in a
mixture of lime and lye or in an acidulated bath, and, after concentra-

page_text: •
tion, the saponification is effected after the mode above described. Or,
the flour may be left to soak in an acidulated bath for many days, and
is afterwards placed in a boiler, when the relative quantities of soda
and lime are added; it is then boiled for some hours, and more
materials may be added. The process is completed by adulteration
and the operations herein-before described. In the use of these two
kinds of substances the processes may be varied, and the operation
carried on either altogether or in part by the hot or cold process, that
is, with or without ebullition.
The quality of the soap will be much improved by adding resin and
essential oils or a mixture of palm oil; and if the material tends to
harden too quickly baths of muriatic acid may be used diluted with
ten to twelve times its volume of water. In these processes it will be
well understood how the system of heating by steam will be preferrable
to that of heating by fire alone, by preventing all chance of the
material burning on the bottom of the boiler. We claim as novel
applications the employment of the following materials or substance:
-
First, essential oils obtained by distilation from schist or coal, wood or
turf. We employ them as adulterants by mixing them with the saponi-
fied matter.
Second, pure pine resin, that is, the juice of the pine from which
turpentine is extracted. We employ it in its native state, and form a
saponified solution of it by dissolving it in a concentrated Iye, but
without boiling, and at a low temperature; to prevent the evaporation
of the essential oil this solution is added to and mixed with soap and
essential oils before the adulterations before mentioned are effected.
Third, rice or potatoe starch may be used. It is first converted into
gelatine by mixing with the boiling lye of a specific gravity of 24 to
$0 degrees Cartier. This is afterwards added to the soap as an adul-
terant.
We make also a resinous soap to add to other soaps, such soaps
being made from yellow resin or pitch, which is ordinarily employed in
the manufacture of yellow soap. The amount to be added being regu-
lated according to the quality of the soap to be made, and in proportions
varying from ten to twenty-five per cent. of saponified matter. We

page_text: operate in two different ways:-In the cold process before described
the resin is first saponified by. heat by boiling some hours in a caustic
alkaline solution of 24 to 30 degrees, afterwards concentrated to
augment its strength. This saponified solution, held in a liquid state
and of the same temperature as the soap itself, is added to it before
adding the adulterants. In the hot process the resin may be mixed
with other matters, and the saponification effected by one single
operation.
The lye pastes, more or less dry, which may be reduced to powder
or placed in moulds of different forms, may be considered as soap of an
inferior quality. We manufacture them in the following manner :-
Instead of exhausting the strength of the lime in the lyes, we draw off
only two waters, and obtain only the first and second lyes, which serve
to make the concentrated lyc. The lime is, however, still saturated
with a large quantity of soda, and should be pulverised and passed
through a fine sieve before being used for the lye; consequently, it.
forms a paste free from grit. We add to it at the least one half of
its weight of powdered white clay, also sifted, or in perfect dissolution
in a sufficient quantity of water for the process. We continue the
ebullition for some time, keeping the mixture stirred. We then intro-
duce in greater or less quantities, according to the quality required,
saponified matter or soap. Resinous and essential oils give also a
good result.
Common salt may also be mixed with it and crystals of
soda. It will be readily understood that it will be useful to charge
these pastes with alkalis, since they will serve to replace the salt of
soda which is usually introduced with soap into boilers for boiling linen.
These pastes may also serve for other purposes, such as the washing
of common cloths, floors, &c.
The fourth part of our Invention relates to the manufacture of crystal
of soda and to certain processes for the employment of common salt and
sea water. Common salt may be employed as an adulterant. It may also
be advantageously employed in the manipulations described in reference
to the manufacture of soap herein-before described, and especially in
mixing with fatty matters; but the principal and most important
purpose for which we employ it is, its conversion into salts of soda,
as herein-after explained. Also, in place of soft water for the lyes
.

page_text: we claim the use of sea water. The soda is introduced into it and
boiled longer than ordinary before adding the lime. The hydrochlorate
of soda or chloride of sodiuni, common salt or marine salt, is converted
into crystals of soda in the following manner :-A saturated solution of
salt is made by one or the other of these two processes, or by adding
common salt to ordinary water, or by taking sea water and evaporating
it until the solution be sufficiently. saturated with salt. The saline
solution thus obtained is placed in a boiler and boiled for some time.
The decomposition of the water is next effected, either by adding to
the solution a mixture of sulphuric acid and iron filings or pieces of zinc,
or by the voltaic pile; during this process a current of pure hydrogen
or hydrogen more or less carbonated, or the hydrogen may be replaced
by a current of oxyde of carbon; carbon or coals, previously dried, may
be placed in the boilers. The operation is continued for some hours,
and the chlorine united to the sodium is separated to become united
with the hydrogen or with the oxyde of carbon; it is extracted
from the water during the process of evaporation, and the soda
is precipitated to the bottom. When the operation is complete,
that is, when nothing but soda and water is left after the admis-
sion of the gas is stopped, as well as the voltaic pile (this latter
not being in action after the commencement of the operation, or
only sufficient to decompose the water), after, also, the coal has been
withdrawn, if any have been used in the solution, dry crystals are
obtained by continuing the boiling and evaporation. But in place of
evaporating, the concentration of the caustic lycs may be proceeded
with at once by adding quick lime, and by continuing the operation as
explained in reference to the manufacture of simple lyes, and their
subsequent conversion into concentrated lyes. The decomposition of
the water effected by one or other of the two processes before described
is not indispensable, but shortens the operation to a great extent, and
renders it more perfect. The crystals of soda contain a considerable
quantity of common salt. If hydrogen gas is preferred, the ordinary
gas employed in lighting may be made use of, or any other obtained by
any means whatever. The system we prefer, however, is by the
decomposition of water by passing steam through a series of pipes
kept at a cherry red or white heat, and we propose also mixing with

page_text: it the vapour of tar in cases where a carbonetted gas is wanted. If
the oxide of carbon gas is preferred, it may also be obtained in various
ways. The following is the process which we consider the most econo-
mical: A furnace of cast iron may be used, lined inside with fire
brick, and made so as to be closed air-tight. It is filled with wood,
charcoal, or coke, and the combustion is kept up by a current of air
forced through it by means of a blower. The air passes off by a con-
ducting pipe, the extremity of which dips into the solution. It is true
that the oxide of carbon will not be pure, and that it will be mixed
with other products of combustion, but without interfering with the
operation. As the gas may be mixed with cinders in its course along
the pipes, a closed receiver is employed in which the cinders are
collected whilst the gas passes along the pipes to the solution. It will
be seen that our two processes for the production of hydrogen and
oxide of carbon possess also the advantage of causing the saline
solution to boil without having recourse to steam or other heating
medium, that is, during the whole of the time that this portion of the
operation lasts.
Having now described and particularly ascertained the nature of our
said Invention, and the manner in which the same is or may be used
or carried into effect, we would observe, in conclusion, that we do not
confine or restrict ourselves to the precise details or arrangements
which we have had occasion to describe or refer to, as many variations
may be made therefrom without deviating from the principles or main
features of our Invention.
In witness whereof, I, the said Pierre Auguste Tourniere, have,
on behalf of myself and of the said Louis Nicolas de Mecken-
heim, hereunto set my hand and seal, this Ninth day of
January, in the year of our Lord One thousand eight hundred
and fifty-four.
TOURNIERE. (L.S.)