Improvements in the Treatment of Common Salt intended to be used for Curing Food, such as Meat, Game, Fish, and Poultry.
Year: 1891

page_text: Date of Application, 19th June, 1891
Complete Specification Left, 19th Apr., 1892-Accepted, 21st May, 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by VICTOR COINET and ALICE JONES, of No. 12,
Rue Notre Dame des Victoires, Paris, in the Republic of France, Operative
Chemists.]
Improvements in the Treatment of Common Salt intended to be
used for Curing Food, such as Meat, Game, Fish, and Poultry.
I AUGUSTUS COLLINGRIDGE of Alderman House Charing Cross Road London in
the County of Middlesex Operative Chemist, do hereby declare the nature of this
invention to be as follows:
With a view to the shortening of the time usually consumed, and arriving at a
simplification as well, in the process of salting and curing such provisions as are
susceptible of being so treated with advantage-I treat the salt intended to be
employed in the curing substantially as follows, by means of which treatment. the
agreeable flavour and beneficial antiseptic effects of smoking the food for a
lengthened period are obtained in one operation of drysalting, or of steeping in
brine or even (as is frequently practised with ordinary brine) of injecting the
brine produced from salt so treated into the meat by means of a forcing pump.
To this end I so direct (by means of destructive distillation carried on in a
suitable retort furnished with necessary connections and attachments) the fumes of
dried peat or of such other suitable ligneous material such as sawdust or wood
shavings, into a mass of loose salt contained in a closed vessel serving as a recipient
for the distillate-so as to cause the salt to be thoroughly impregnated with the
resultant of the destructive distillation of the material used in the retort taking the
precaution in the early stage of the operation to have driven off in a separate
direction by the mode of fractional distillation any water or tar contained contained
in the peat or woody substance employed.
The test for ascertaining the fact of the effective impregnation of the salt
consists in observing the darkened colour of the mass, and further by the free
condensation of the vapour into liquid acid, when the supply should be shut off from
that particular lot of salt; and, if the operation is continuous, diverted into a
separate recipient of loose salt.
Common salt treated as above whether used for drysalting or conversion into brine
possesses the advantages set forth above. In certain cases when the operation of
distillation is rendered impracticable through the absence of suitable machinery
and pyroligneous acid itself is procurable I may add to the raw salt in bulk from five
to ten or even fifteen per cent. (reckoning liquids by measure and solids by weight)
of such acid according to the specific gravity of the same denoting the degree of
concentration or dilution as the case may be. But this method of incorporating
the acid with the crystals of the salt altho' it may be adopted as a substitute is
inferior to that of directing the fumes (freed from water and tar) into a mass of
loose salt contained in a closed vessel.
Dated this Fifteenth day of June 1891.

page_text: COMPLETE SPECIFICATION.
Improvements in the Treatment of Common Salt intended to be
used for Curing Food, such as Meat, Game, Fish, and Poultry.
I AUGUSTUS COLLINGRIDGE of Alderman House Charing Cross Road in the
County of Middlesex Operative Chemist do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
With a view of materially abridging the time necessarily consumed as well as
simplifying the processes ordinarily adopted in respect of dry or wet salting
combined with curing by smoking such species of meat game fish and poultry as
are susceptible of being salted and smoked with advantage-I treat the salt
intended to be employed in the curing substantially as follows by means of which
treatment the use of such salt ensures the obtention in one operation of short
duration of the agreeable flavour and antiseptic effects of otherwise smoking the
food for a lengthened period in kilns or smoking chambers such periods in the case
of highly dried articles frequently extending to three weeks. Whereas by the use
of my process under any circumstances whether the meat is dry salted or steeped in
liquid brine or, as frequently practised, the brine is injected by means of a force
pump only the requisite time is required for the salt to strike or penetrate
throughout the meat. To this end I so direct by means of combining destructive
with fractional distillation, carried on in a suitable retort furnished with the
necessary connections the neck or main delivery pipe of which retort contains an
adjustable diaphragm constructed of porous material (such apparatus being of a
kind too well known in operative chemistry to require more particular description
here) the fumes or vapour arising from the distillation of peat (in a more or less
dessicated condition) or of such other ligneous or fibrous material as may be
suitable for the purpose into a mass of loose salt contained in a closed tank or
vessel furnished with a suitable lid or cover, such tank or vessel being so connected
with the retort as to serve as a recipient for a portion of the distillate described
below. If the mother solid matter in the retort consists of wood or preferably
wood sawdust or shavings such matter should be selected from the hardest and
least resinous species.
In the early stage of the operation in order to obtain the best result, care must
be taken to draw off into a separate recipient any undesirable excess of free water
or tarry matter originally existing in the wood or peat, and when this is considered
to have been effected the delivery of vapour may be directed into the mass of salt
contained in the recipient before described and such delivery continued until the
whole of the crystals are thoroughly impregnated. The test I employ in practice
for ascertaining the fact of the effective saturation of the salt consists in observing
the darkened colour of the crystals succeeded by a somewhat rapid condensation of
the vapour into liquid when the supply from the generating retort may be shut off
or diverted elsewhere. The addition to the recipient of an agitator of ordinary
construction as to its working parts I have found extremely advantageous.
Salt so treated is immediately fit for dry salting or conversion into brine and
ready for effecting the objects above mentioned.
In cases where the process of distillation is rendered impracticable through the
absence of suitable apparatus, and of properly selected materials-but where the
pyroligneous acid of commerce is procurable I may add to the raw salt in bulk
from 5 to 10 or 15 per cent. (reckoning solids by weight and liquids by measure) of
such acid being in some measure guided (if the only certain test of the volumetric
proportion of solution of soda requisite for neutralization be not available) as to
quantity by the specific gravity of the acid approximately denoting its degree of
concentration. But the result of this operation performed in the absence of sure
chemical tests is often uncertain and disappointing in comparison with the superior

page_text: process of distillation hereinbefore described by reason that the pyroligneous acid
of commerce being ordinarily manufactured from materials miscellaneous in their
character, is characterised by a deleterious burning acidity which is apt to
communicate a rank flavour to the meat and by uncertainty as to the degree of
anhydrous acid contained in samples of similar specific gravity, in addition to
which much difficulty is experienced in arriving at a uniform mixture of small per-
centages of acid with large quantities of salt in bulk. For which reasons although
the antiseptic properties of the salt will be enhanced and the salt imbued with the
savour of smoke, I prefer the former method.
Having now particularly described and ascertained the nature of my invention
and in what manner the same is to be performed and carried into effect I declare
that what I claim is :-
1st. The treatment of common salt by causing fumes arising from the destructive
and fractional distillation of peat wood or other suitable fibrous matter to pass into
or through masses of loose crystals of such salt substantially in the manner and for
the purposes and objects hereinbefore set forth and described.
2ndly. The treatment of common salt intended to be employed in salting and
curing certain enumerated articles of human food by means of adding thereto and
mixing therewith the pyroligneous acid of commerce in certain given proportions
which however may be varied as occasion may require for the purpose of imbueing
the salt with the savour of smoke and augmenting the antiseptic properties of such
salt and further by use of salt so treated materially abridging the time hitherto
usually occupied in salting and curing the before mentioned articles of food.
Dated this 19th April 1892.
A. COLLINGRIDGE.