AN IMPROVED PROCESS FOR THE REGENERATION AND RECOVERY OF HYDROCHLORIC ACID WHICH HAS BEEN USED IN THE TREAT- MENT OF BONES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 1st April 1881. A communication
from abroad by the "Société Coignet Pére et fils et Compagnie," of Paris,
France.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED PROCESS FOR THE REGENERATION
AND RECOVERY OF HYDROCHLORIC ACID WHICH HAS BEEN USED IN THE TREAT-
MENT OF BONES." A communication from abroad by the "Société Coignet Pére
et fils et Compagnie," of Paris, France.
The bones of animals used in the manufacture of glue and gelatine consist of
two distinct elements, viz., the organic element and the mineral element. The
mineral element or portion consists chiefly of tribasic phosphate of lime and of
carbonate of lime, and the organic part is formed of a homogeneous azotized sub-
stance, which has been termed "osseine," and which when boiled in water is
transformed into gelatine.
The separation of the mineral part of bones from the organic part thereof can
be effected under certain conditions.
If bones, previously freed from fat; are submitted to the action of water raised
to a temperature exceeding 100° centigrade in a closed vessel, the organic part is
dissolved in the water. The mineral part termed "degelatinized
bone (os
dégélatiné) remains in the form of bone, and the solution when evaporated for the
purpose of concentrating the same, produces a jelly which congeals when cooled, and
this is glue.
On the other hand, when bones are submitted to the action of hydrochloric
acid diluted with water, the hydrochloric acid dissolves the mineral part of the.
bone, and there remains an elastic substance retaining the form of the bone,
which substance is the osseine, and by being boiled in water is transformed into
gelatine.
The reaction produced in the dissolution of the mineral part by hydrochloric acid.
is as follows, viz. :-
Ph O 3 Ca O + CO³ Ca O + 3 C1 H=Ph O³ Ca O 2 HO +-3 Ca Cl+Co³ + HO.

page_text: obtained by the said reaction, contains acid, phosphate of lime, and chloride of
calcium.
Hitherto the liquid so obtained has been used for preparing precipitated bibasic
and tribasic phosphates by precipitating the same with lime.
According to this Invention, sulphuric acid is added to the liquor obtained in
the treatment of bones by hydrochloric acid, and the following reactions take place,
that is to say: If the quantity of added sulphuric acid is sufficient to precipitate
all the lime in the liquid, the following is the reaction, viz. :-
Ph O³ Ca O 2 HO+ Ca Cl + 2 SO³=2 SO³ Ca O + Cl H + Ph O³ + HO.
As will be seen, the lime is entirely precipitated in the form of a sulphate, and
the solution contains a mixture of hydrochloric and phosphoric acid.
If on the contrary only an insufficient quantity of sulphuric acid is added, the
latter precipitates the lime in the chloride of calcium, and the following reaction
takes place
-
Ph O³ Ca O 2 HO+Ca Cl + SO³=SO³ Ca O + Pho³ Ca O 2 HO + Cl H.
As will be seen in this case, the liquid obtained after the sulphate of lime
has settled contains a mixture of acid, phosphate of lime, and hydrochloric acid.
Thus, in the first case, the liquid contains a mixture of hydrochloric acid and
phosphoric acid, and in the second case the liquid contains a mixture of hydrochloric
acid and acid phosphate of lime.
The materials may be treated either when cold or when heated. Whichever of
the two processes may have been used, if the liquid is submitted to boiling the
hydrochloric acid is set free, and there will be obtained in the first case a solution
of phosphoric acid, and in the second case a solution of acid phosphate of lime,
both of which may be used in the manufacture of phosphorus, and of phosphates
of various kinds, and superphosphates of lime such as used for agricultural
purposes.
The hydrochloric acid expelled by boiling may be condensed by water in any
suitable apparatus, and thus a solution of hydrochloric acid is again obtained, which
may be used for treating a further quantity of bones.
If before the expulsion of the hydrochloric acid by boiling it is desired to use
for again treating bones, the solution consisting of either phosphoric acid and
hydrochloric acid, or of hydrochloric acid and acid phosphate of lime, it will suffice
to place the bones in contact with this solution, and the hydrochloric acid may be
expelled only after so enriching the liquid with phosphoric acid or acid phosphate a
of lime.
The acid liquid produced in the treatment of bones may be treated with sulphuric
acid in vessels of any suitable form, and made of wood, sheet-iron, copper, or the
like. For condensing the hydrochloric acid expelled by boiling, any of the apparatus
at present applied to this purpose may be used.
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