A New Process of Preserving Alimentary Substances.
Year: 1893

page_text: Date of Application, 19th June, 1893-Accepted, 26th Aug., 1893
COMPLETE SPECIFICATION.
[Communicated from abroad by PIERRE GABRIEL BIRON, of Argenteuil
(Seine et Õise), France, M.D.]
A New Process of Preserving Alimentary Substances.
I, ERNEST DE PASS, of 78, Fleet Street, in the City of London, Fellow of the
Chartered Institute of Patent Agents 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, that is to say:—
This invention has for its object the preservation of articles of food, such as
meat, fowl, game, eggs, fish, crustacea, and the like, either raw or cooked, by an
easy and inexpensive chemical process; preservation being ensured for a longer or
shorter period of time, according to the manner in which the reagents are used, or
the proportions in which they are mixed in each particular case, and also according
to the preparatory manipulation undergone by the substances to be preserved.
Whatever the conditions under which the process is carried out, the substances
treated will, in every case, prove. perfectly innocuous and incapable of either
impairing the health generally or causing the slightest disorder in the digestive
organs.
The process is based entirely upon the action of nascent hydrochloric acid gas,
produced, say by means of a supersaturated solution of chloride of sodium, or
marine salt, treated with sulphuric acid.
To prepare the hydrochloric acid gas, a solution saturated with chloride of
sodium may be poured into a vessel or receptacle of any suitable size, an excess
of salt being added to it. I then pour in sulphuric acid, whereupon hydrochloric
acid gas is disengaged in the form of dense fumes. If at the very moment of the
reaction care be taken to close the vessel with a cover, from which a piece of meat,
for instance, is suspended, there will be obtained after a few minutes contact with
the fumes a substance which has become imputrescible.
a
The apparatus which has been employed in making experiments simply consists
of a wooden box, lined with a sheet of india-rubber capable of resisting the action
of the acid vapours. The box is provided with a cover or lid furnished with
hooks, from which the substances under treatment are suspended. At the bottom
of the box is placed a saucer-shaped receptacle and at one side of the box, a little
above the level of the said receptacle, is an opening provided with a sliding door,
through which a small glass or china vessel, fitted with a long handle, may be
readily introduced. Having first placed supply of saline substance into the
saucer, the articles to be treated,are suspended from the cover, then, by opening the
side door the sulphuric acid is poured in by means of the long handled vessel.
The sliding door, or shutter, is then immediately closed, and an energetic reaction
takes place and the box becomes rapidly filled with hydrochloric acid gas.
allowing the substance, or substances, under treatment, to remain in contact with
the gas for from five to ten minutes, such substances may be removed from the
apparatus when, on being exposed to the open air for several hours, they will
remain for a long time in a fit state for consumption. The proportions of the
reagents to be used, may vary according to the greater or less length of time for
which it is desired to preserve the food; the average proportions for one cubic
metre of substance to be preserved being :
After
2000

page_text: During the operation, a space of at least 15 centimetres should be left free above
the edges of the saucer, and the immersion in the gas should be continued for from
five to ten minutes. It is also preferable, after the operation, to allow the meat, or
the like, to remain exposed to the air for a number of hours as this will render
preservation still more reliable; a fact which cannot at the present moment be
accounted for, except by supposing, either that oxidation sets in, or that the
albumen on the surface of the meat is coagulated, as it were, thereby excluding
deleterious germs. These however are merely hypothetical assumptions. But,
whatever the real cause of the phenomenon may be, the fact remains that provided
the temperature of the ambient air is moderate, meat thus treated will continue
practically fresh for a certain number of days. As the time of the chemical
treatment becomes more remote, gradual desiccation will naturally take place owing
to the slow evaporation of the water contained in the tissues. Several months
after, the fatty substance will be found to have dried, and the muscles hardened as
though the meat had been smoked a long time, but no putrefaction or decomposition
will have set in, and the nutritive properties will still be entirely preserved. By
boiling such meat in water, its original volume will be restored, while the broth
retains in a surprising degree its good quality and pleasant savour. If it be
intended to carry the meat from place to place in bulk, or in bags, say for troops
in the field, it is wise not to pack it till several days after its preparation when
superficial desiccation has had time to commence. From the foregoing description
it will be seen that the process is both easy and cheap. It may be added that for
its performance on a large scale for industrial purposes no special apparatus is
required, as any chamber or room may be used, which still more simplifies the
operation.
In applying the process to crustacea and eggs, the crustacea, after being cooked,
are hooked into the box, and fresh eggs are placed in a suitable basket which leaves
nearly the whole of the shell uncovered; they are then subjected to the hydrochloric
vapour. As the carapace of the crustacea. as well as the shell of the eggs, are in
a great part composed of calcareous salts, a chemical decomposition, only slightly
appreciable, is produced on the surface, the result of which is to convert the
external coating into chloride of lime, the probable cause of the preservation.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I claim:
1. The herein described process of preserving alimentary substances, consisting
in immersing them in nascent hydrochloric acid gas produced by any suitable
process, but preferably by the reaction of sulphuric acid on chloride of sodium,
said substances being mixed in such proportions as to suit requirements.
2. The employment of the herein described process for any alimentary industrial
purpose to which it may be applicable.
Dated this 10th do of [1900