IMPROVEMENTS IN THE TREATMENT AND PURIFICATION OF COD LIVER OIL
Year: 1879

page_text: LETTERS PATENT to John Fordred, of Tottenham, in the County of Middlesex,
Technical Chemist, for the Invention of "IMPROVEMENTS IN THE TREATMENT
AND PURIFICATION OF COD LIVER OIL."
ealed the 26th August 1879, and dated the 16th May 1879.
PROVISIONAL SPECIFICATION left by the said John Fordred at the Office of
the Commissioners of Patents on the 16th May 1879.
JOHN FORDRED, of Tottenham, in the County of Middlesex, Technical Chemist.
" IMPROVEMENTS IN THE TREATMENT AND PURIFICATION OF COD LIVER OIL."
The object of the present Invention is the treatment of cod liver oil, in order to
render it more fitted for medicinal use, by removing as far as possible the nauseous
taste and odour it naturally possesses.
Cod liver oil, as found in commerce, varies very considerably; this is due to two
causes, its mode of manufacture, and its age. If the oil has been kept some time it is
more difficult to sweeten; it is advisable therefore to operate on oil as recently
prepared as possible.
The agencies I make use of are steam, hot water, acids, acid salts, and vegetable
charcoal. These have not hitherto been applied to the treatment of cod liver oil,
the usual plan being to mask or disguise the disagreeable taste of the oil by adding
to it some flavoring ingredient, such as mirbane or the oil of winter-green.
I find the simplest mode of sweetening the oil is to wash it well with hot water,
using therewith a jet of steam, then let it settle, draw off the oil, add some ground
vegetable charcoal to it with agitation and warmth, and finally filter.
I
The flavoring principle of the oil being of an alkaline nature, I find it advantageous
to acidulate the water slightly with which it is steam washed; then, after repose,
draw off the oil and add the charcoal, at the same time warming and agitating the
mixture, and I then filter it.
A third mode of purification is to agitate the oil with the charcoal and a weak
vegetable acid, such a citric or tartaric acid in powder, and with or without heat,
and then filter it.
In some cases it may not be necessary to use all the agencies above named, or
follow the exact sequence indicated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Fordred in the Great Seal Patent Office on the 15th November
1879.
JOHN FORDRED, of Tottenham, in the County of Middlesex, Technical Chemist.
"IMPROVEMENTS IN THE TREATMENT AND PURIFICATION OF COD LIVER OIL."
The object of the present Invention is the treatment of cod liver oil, in order to
render it better fitted than heretofore for medicinal use by removing as much as
possible the nauseous taste and smell it naturally possesses.
*
Cod liver oil, as found in commerce, varies very considerably, this variation being
due to two causes, its mode of manufacture, and its age. If the oil has been kept
some time it is more difficult to sweeten; therefore it is advisable to operate on oil
as recently prepared as possible.
Considering the very delicate nature of cod liver oil and the purposes to which
it is applied, it is evident that any chemical process employed to purify it must be
of a very mild character and totally different to the powerful oxidizing treatments
ordinarily made use of in refining non-medicinal oils. A treatment that is sufficient
to sweeten cod liver oil would not produce any appreciable effect on such oils as
linseed, rape, cotton seed, and the like; this must be constantly borne in mind by
the operator.
The agencies I find available for this purpose are the following, viz., steam, steam-
heat, hot water, acids, acid salts, and vegetable charcoal. These have not hitherto
been employed in the purification of cod liver oil, the usual plan being to mask or
disguise the disagreeable taste of the oil (instead of removing the same) by adding
to it some flavoring ingredient, such as mirbane, balsam of Peru, or the oil of
winter green.
I find the simplest mode of sweetening the oil is to wash it well with hot water,
using therewith jets of steam, then to let it settle, draw off the oil, add some ground
vegetable charcoal to it with agitation and warmth, and finally filter.
The flavoring principle of the oil being of an alkaline nature, I find it advan-
tageous to acidulate the water slightly with which it is steam-washed; then, after
repose, I draw off the oil and add the charcoal, at the same time warming and
agitating the mixture, and I then filter it.
A third mode of purification is to agitate the oil with the charcoal and a weak
vegetable acid, such as citric or tartaric acid in fine powder, and with or without
heat, and then filter it.
In carrying my Invention into practice I proceed in the first case as follows:-
I place, say, ten gallons of cod liver oil in a clean earthenware vessel, in the bottom
of which is fitted a perforated steam coil, preferably made of pure silver or pure
tin, and add to it about three gallons of warm water. I then blow in free steam
for a few minutes through the perforated coil until the disagreeable smell is in great
part if not wholly removed. I then shut off the steam and allow the oil to separate
from the water and impurities.. After a few hours repose the oil is drawn off and
mixed in a second earthenware vessel with five ounces of finely sifted vegetable
charcoal; this second vessel is fitted with a close steam coil, made preferably of pure
silver or pure tin, by the aid of which the mixture is heated up to one hundred and
twenty degrees Fahrenheit whilst being gently agitated, after which the oil is cooled,
filtered, and stored in well closed vessels.
In my second method of purification I use a suitable weak acid or an acidulated
water in lieu of the plain water mentioned above, one mode of preparing which is
as follows:-
I dissolve eight ounces of citric acid in three gallons of warm water, and steam-
wash the ten gallons of oil with one gallon of this solution in place of the three
gallons of plain water before mentioned, and I then proceed with the treatment
above described and finish in the same manner.

page_text: If desired tartaric acid or other suitable acid may be substituted for the citric
acid above mentioned. If stronger acids are used they must be reduced to a corre-
sponding strength.
Or acid salts, such as bitartrate of potash or the like, may be used in place of the
acids in making the above solution.
Some cod liver oils will require the acid solution to be made stronger, and the
steam washing to be continued longer than others; the operator inust therefore be
guided in some measure by the condition of the oil under treatment; the steam-
washing operation should not however be continued for more than twenty minutes.
According to my third mode of purification I mix ten gallons of the oil to be
treated with five ounces of finely sifted vegetable charcoal and ten ounces of finely
powdered tartaric acid, and agitate them well together whilst the temperature is
gradually raised to one hundred and twenty degrees Fahrenheit, and when settled
and cold I filter the oil till thoroughly bright and preserve it in well closed
vessels.
The charcoal to be used for the above mentioned purposes must be vegetable
charcoal, and I prefer to use finely levigated box wood or acacia charcoal.
I would remark that wherever in the above Specification I have prescribed a
particular temperature, or proportion of material, or time to be employed in the
several processes, it must be understood that I do so merely as indicating that which
I have found most efficacious, but I do not limit myself to such temperature, or
proportions, or time, as variations in temperatures, or proportions, or duration of
time may be introduced, and results of like character to those which I have described
may be attained.
Having now set forth the nature of my Invention of "Improvements in the
Treatment and Purification of Cod Liver Oil," and explained the inanner of carrying
the same into effect, I wish it to be understood that under the above in part
recited Letters Patent I claim,-The treatment and purification of cod liver oil in
the manner substantially as above described.
In witness whereof, I, the said John Fordred, have hereunto set my hand
and seal, the Fifteenth day of November, in the year of our Lord One
thousand eight hundred and seventy nine.