In- PROVEMENTS IN THE MANUFACTURE OF SOAP
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Ulysses De Lungo at the Office
of the Commissioners of Patents, with his Petition, on the 7th
November 1873.-A communication from abroad by Gaetano
Tardani, of Rome, in the Kingdom of Italy.
I, ULYSSES DE LUNGO, of Cannon Street, in the City of London,
Merchant, do hereby declare the nature of the said Invention for "In-
PROVEMENTS IN THE MANUFACTURE OF SOAP," to be as follows :-
―
The object of this Invention is to economize time, fuel, labour, and the
preliminary expenses in the manufacture of soap, to render more remune-
rative the capital invested in such manufacture, and to facilitate the
production of secondary useful substances, more especially of glycerine.
To carry out the Invention take any convenient quantity of oil or suct
or other fatty matter, and place it in a flat bottomed boiler of iron con-
structed in the form of a truncated conė, together with double the
quantity of water and a proportion of oxyde of calcium or quicklime,
rendered previously slack by means of a certain quantity of water cqual
to 12 per cent. of the weight of the oil or fat. The whole must be boiled
and mixed by means of an agitator, a mechanical one by preference.

page_text: This will produce an insoluble hard lime soap and a solution of glycerine,
the latter of which may be separated by opening the top of the gauzed
or perforated pipe connected with the bottom of the boiler.
After having washed a little the lime soap and closed the top to the
lime soap is added a certain quantity of water and a quantity of com-
mercial carbonate of soda equivalent to or rather in excess of the
quantity of lime used.
When these ingredients are well mixed and the mixture boiled the
hard insoluble lime soap will be decomposed, and the lime will be pre-
cipitated in the form of a granular carbonate, while a soluble soda soap,
or potash soap (when potash is used for the purpose of having soft soap)
is produced which floats in the shape of flakes on the top of the water,
more especially if sea salt has been added to provide for the case of the
soda not containing a sufficient quantity of salt. This is the reason why
the shape of a truncated cone is preferred for the boiler, and its bottom
is made flat and the communication of heat only round the boiler is
used. It is in this way that it is possible to make good soap, using fatty
matter with membranes and very impure oils without having to bear
the expense for extracting the pure fat or oil. If cocoa nut oil or palm
oil are to be saponified, a quantity of lime equivalent to the fifth of their
weight can be used. These soaps being very soluble even in salt water
it is necessary to make use of tolerably pure carbonates of the alkali.
Considering that lime (so little soluble in cold water) is far less
soluble in hot water, and that to such scarcely sensible alkalinite of it is
due the period of eight hours, which is required by the lime to
produce the desired saponification, I had recource to a certain quantity
of carbonate of soda to give the liquid a density of three degrees, the car-
bonate of soda becoming at once hydrated acts at once upon the fat or oil,
so that as soon as it has become soda soap the latter converts itself into
lime soap, thence a further economy of force, fuel, and time. The liquid
remaining after the first saponification contains in addition to hydrate of
soda about roths of glycerine, and by being used three or four times over
again instead of plain water, will in the end become so charged with
glycerine, that this latter useful product will be supplied with great
economy in addition to the soda which will be saleable.
To
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page_text: former even taking into account the lime in excess mentioned, and the
impurity on the other hand of the commercial litharge, and that the
action of the oxyde of lead is assisted by that of the alkaline hydrate,
which in this case it does not matter whether it contains a small
quantity of lead), it is evident that another secondary product, viz., white
lead, could be cheaply obtained. For this case it is well to remember
1st, the necessity of using clear oils or pure grease, and 2ndly, a vessel
of copper in order to prevent the well known action of iron on lead salts
which might be overlooked in this case on account of the solubility of
lead salts and the electro-negative character of the iron for its contact
with alkali solution.