IMPROVEMENTS IN THE TREATMENT OF BONES AND IN THE MANUFACTURE OF PAPER
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by Thomas Richardson at the Office of
the Commissioners of Patents, with his Petition, on the 21st September
1860.
I, THOMAS RICHARDSON, of Newcastle-upon-Tyne, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE TREATMENT OF BONES
AND IN THE MANUFACTURE OF PAPER," to be as follows:-
The chief object of the Invention is to obtain from bones a diphosphate or
subphosphate of lime in the state of a fine white powder or precipitate suitable
for being employed in the manufacture of paper in lieu of sulphate of lime or
other white powders and which renders the paper smoother and generally of
better quality. This diphosphate of lime is a totally distinct compound from
the superphosphates or biphosphate of lime obtained by acting on bones with
strong sulphuric acid for the manufacture of manure. The biphosphate or
superphosphate of lime is soluble in water, and therefore inapplicable to the
manufacture of paper, but the diphosphate or subphosphate of lime which I
obtain is insoluble in water. The apparatus which I employ consists of one
or more towers or columns of circular, rectangular, or other suitable section,
and constructed of wood, lined with lead, or of fire-brick or stoneware, or of
other suitable material capable of resisting the action of sulphurous acid.
These towers are filled with bones which may be supported on frames or
stages at intervals and introduced or removed by doors or apertures. The
bones may be previously cleaned by steeping in lime water and washing, and

page_text: the larger bones may be crushed or broken. A stream of sulphurous acid
gas obtained by any known means is caused to pass through the towers. The
towers are connected so as to form one continuous channel or passage, and
the last tower is connected with a chimney, or a sulphuric acid chamber, or an
exhausting apparatus so as to draw the gas through them. The towers are
supplied with a current of water or of weak solution from some of the towers,
which meeting the sulphurous acid absorbs it and dissolves out the earthy matter
of the bones, a portion of the lime in the bones combines with the sulphurous acid
leaving a diphosphate of lime which (although insoluble in pure water), is soluble
in a solution of sulphurous acid. In this process care must be taken that the
temperature does not rise so high as to dissolve the gelatine of the bones. The
liquid may thus be brought to a strength of fifteen degrees of Twaddell's hydro-
'meter, but I prefer to mix it with weaker solutions, and to digest clean softened
bones in them to absorb as much as possible of the free sulphurous acid, I then
-evaporate or concentrate the solution until the diphosphate of lime precipitates,
or I mix the solution with as much lime or magnesia, or their bicarbonates in
solution, as will supply another equivalent of these bases to combine with the
sulphurous and phosphoric acids, and I collect the precipitated subphosphates of
lime, which are afterwards dried in the air or otherwise. A fine white powder
is thus obtained, which I employ in the manufacture of paper by mixing it
with the ordinary paper pulp. The animal matter or gelatine of the bones is
removed from the towers when the earthy matter has been extracted and is
carefully examined. The finest portions are well washed and then dissolved
in hot water strained and evaporated in vacuo or otherwise so as to obtain a
nearly colourless gelatine. The next portions are made into glue and the
most impure portions are dried and used in lieu of other animal matter in the
manufacture of prussiate of potash.