IMPROVEMENTS IN THE EXTRACTION OF GELATIN, FAT AND SIMILAR SUBSTANCES FROM BONES HIDES FISH AND AT
Year: 1883

page_text: LETTERS PATENT to Carl Daniel Ekman of Sweden but now of 57, Old
Broad Street in the City of London Chemist for an Invention of
IMPROVEMENTS IN THE EXTRACTION OF GELATIN, FAT AND SIMILAR
SUBSTANCES FROM BONES HIDES FISH AND
ATHED
PROVISIONAL SPECIFICATION left by the said Carl Daniel Ekman at
the Office of the Commissioners of Patents on the 30th May 1883.
D
CARL DANIEL EKMAN of Sweden, but now of 57 Old Broad Street in the City
of London Chemist "IMPROVEMENTS IN THE EXTRACTION OF GELATIN FAT
AND SIMILAR SUBSTANCES FROM BONES, HIDES, FISH AND OTHER ANIMAL MATTER
The object of this Invention is to extract from bones, hides fish or other
substances of animal origin their useful constituents (such as gelatin and fat) in
such a manner as to obtain products of quality and colour superior to those
obtained by the ordinary methods and it consists in boiling the raw materials
under pressure in solutions containing sulphurous acid with a base or alkali.
In carrying out this Invention the substance to be treated is reduced by any
suitable mechanical means to such a condition that during the subsequent boiling
process the liquid employed may be able to permeate it.
The substance thus prepared is placed in a boiler or vessel of the construction
now generally used for boiling under steam pressure vegetable substances. in
solutions containing sulphurous acid and it is lined with lead or other metal or
alloy capable of resisting the action of the chemicals employed or it may be wholly
of such suitable metal or alloy.
The boiling solution from which I have obtained the best quality of gelatin
(from fresh bones) has been one containing sulphurous acid and a base in the
proportions forming the salt commonly called the bisulphite (though the sulphite
may be used) and the base I have found generally preferable has been magnesia.
With such a solution a pressure between 5 lbs and 10 lbs to the square inch has
given good results.

page_text: The object of the employment of a base together with sulphurous acid is that
when free sulphuric acid is present in solution or is formed during the boiling
process it may be at once neutralized by the base and the injurious effects produced
by free sulphuric acid thereby prevented. It will be obvious therefore that when
the raw material treated contains a considerable quantity of base (for instance in
the case of bones which contain a large percentage of lime salts) free sulphuric acid
would be neutralized, by the base present in the raw material itself. When however I
have employed sulphurous acid alone the gelatin produced has shewn more tendency
to become liquified (ie. the jelly formed on cooling is less solid) than when a
solution of sulphite or of bisulphite has been used. I therefore consider it preferable
to use solutions containing the base in a soluble form (as sulphite or bisulphite)
even in treating raw material such as above referred to. When the production of
gelatin is not the special object in view then the pressure employed may exceed
10 lbs to the square inch. For instance when fresh bones have been treated at
90 lbs pressure with a solution of bisulphite or sulphite of magnesia, fat of good
quality and color has been obtained but under these conditions the gelatin contained
in the bones is not present in the liquid obtained in such condition as to gelatinize
or (form a jelly) on cooling
I have found it necessary in order to extract the whole of the gelatin from bones
to repeat the boiling operation.
When gelatin of superior quality is desired it is of great importance that the
heating during the boiling operation should be very gradual so as to avoid too high
a temperature in any part of the liquid.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Daniel Ekman in the Great Seal Patent Office on the
30th November 1883.
CARL DANIEL EKMAN of Sweden but now of 57%, Old Broad Street in the
City of London Chemist IMPROVEMENTS IN THE EXTRACTION OF GELATIN
FAT AND SIMILAR SUBSTANCES FROM BONES HIDES FISH AND OTHER ANIMAL
MATTER
The object of this invention is to extract from bones hides fish or other
substances of animal origin, their useful constituents (such as gelatin and fat) in
such a manner as to obtain products of quality and color superior to those
obtained by the ordinary methods and the invention consists in boiling the raw
materials under pressure in solutions containing sulphurous acid with or without a
base or alkali
In carrying out this Invention the substance to be treated is if necessary
properly cleaned then reduced by any suitable mechanical means to such a
condition that during the subsequent boiling process the liquid employed may be
able to permeate it, the attainment of this object may in some cases be assisted by
exhausting the air from the bones previous to the introduction of the solution used
in boiling-The substance thus prepared is placed in a boiler or vessel of the
construction now generally used for boiling under steam pressure vegetable sub-
stances in solutions containing Sulphurous Acid (preferably heated by means of a
Steam jacket) and it is lined with lead or other metal or alloy capable of resisting
the action of the chemicals employed or it may be constructed wholly of such
suitable metal or alloy.
The boiling solution with which I have obtained the best quality of gelatin
(from fresh bones) has been one containing sulphurous acid and a base in the
proportions forming the salt commonly called the bisulphite and the base I have
found generally preferable has been magnesia.
With such a solution a pressure of about five pounds to the square inch has given
good results.
If a solution of sulphurous acid alone (without a base) be employed under the.
same conditions I have found the result less satisfactory.
In this case the gelatin is more apt to become liquified (i. e. the jelly formed on
cooling is less solid) and the color generally is not quite so good.
When the production of fat is the main object in view then the pressure employed
may exceed Ten pounds to the square inch
For instance when fresh bones have been treated at Ninety pounds pressure
with a solution of bisulphite or sulphite of magnesia fat of good quality and color
has been obtained but under these conditions the gelatin contained in the bones
is not present in the liquid obtained in such condition as to gelatinize (or form a
jelly) on cooling.
In cases where the complete extraction of the gelatin and fat contained in the
bones is desired it will be found generally necessary to repeat the boiling
operation
When gelatin of superior quality is desired it is of great importance that the
heating during the boiling operation should be very gradual so as to avoid too high
a temperature in any part of the liquid
The strength of the solution which I have found suitable is one which contains
about three quarters per cent of sulphurous acid

page_text: Having thus given general principles to guide the operator I proceed to give
an example of a convenient method of carrying out this Invention in practice
Supposing it is desired to prepare gelatin of superior quality I select good fresh
bones (or if not fresh preserved from change in their constituents by antiseptic or
other suitable treatment) These bones are freed from foreign matter by any
suitable mechanical or chemical means and are then broken into small pieces (the
size commercially known as half inch bones I consider very suitable). They are
then placed in a boiler of the construction above directed-A solution of bisulphite
8f magnesia is then prepared of such a strength that it shall contain about three
quarters per cent of sulphurous acid and with this the boiler is filled to such extent
that the bones shall be entirely covered by liquid during the whole boiling process-
The boiler is then closed and the temperature gradually raised until the pressure
reaches about five pounds to the square inch at which point it is maintained for
about three hours-The steam is then blown off and the liquid divided from the
solids by any suitable means-The liquid is then allowed to cool when the
impurities gradually 'subside while the fat rises to the top of the solution of
gelatin The separation of the solution of gelatin from the fat and from the
impurities can then be easily effected by any suitable means and it can be used as
it is or evaporated in the usual way or if it is desired to use it for some purpose
where the admixture of salts of sulphurous acid is objectionable, these can be
removed more or less perfectly by chemical means such as by baryta
The fats obtained from bones by this method are partly fluid and partly solid
Having thus described the nature of my invention and the mode of carrying it
into effect I would have it understood that I do not confine myself to the propor-
tions of chemicals strength of solution amount of pressure or duration of boiling
which I have described but what I claim as of my invention is
The manufacture of gelatin fat and similar substances from bones hides fish and
other substances of animal origin by boiling under pressure in a solution containing
sulphurous acid with or without a base or alkali
In witness whereof I the said Carl Daniel Ekman have hereunto set my hand
and seal the twenty eighth day of November in the year of our Lord One
thousand eight hundred and eighty three
Witness
:
W. H. SPENCE
8 Quality Court, Chancery Lane
Patent Agent
C. D. EKMAN (L.S.)