Year: 1887

page_text: Date of Application, 3rd Mar., 1887
Complete Left, 25th Nov., 1887.
Complete Accepted, 27th Dec.. 1887
I CARL ADOLF SAHLSTRÖM of Albert Quay in the City of Aberdeen Gentleman do
hereby declare the nature of this invention to be as follows:-
22
By extensive experiments it has been ascertained that there is a relation between
the disappearance of the "rigor mortis of fish and other animals and the beginning
of putrefaction, and that the rate of the putrefactive process to a large extent depends
on the amount of gases and fluids present in the tissues. Further, it has been
shown that even the earliest stages of putrefaction are associated with the presence
of Bacteria, and other minute organisms, and that when the invasion of the tissues
by Bacteria is prevented, not only putrefaction delayed, but the "rigor
stiffening is maintained.
"
or
Hence in preserving fish, it is necessary to treat them before the rigor has passed
off, and either to prevent Bacteria reaching them, or to render the muscles &c.
incapable of providing the Bacteria with the nourishment necessary for their growth
and development.
Hitherto, common salt has been chiefly used for preserving fish.
When salt is used in the ordinary way it is necessary to use a 20 per cent. solution.
This strong solution, while it effectively prevents the growth of Bacteria, so alters
the tissues that they are no longer either so nourishing, palatable or digestible.
Sometimes Boric (Boracic) and other acids, are used, either alone or with salt and
other chemicals, all of which are more or less objectionable, when sufficient is used
to preserve the fish, even when they are kept under considerable pressure.
As the result of numerous chemical and other investigations, I have devised the
following method of preserving which commends itself chiefly because, by only
requiring the smallest possible amount of salt or other preservatives, the tissues are
left almost unaltered.
The fish &c. to be preserved are obtained before putrefaction has set in, or as soon
as possible after the rigor has disappeared, (the rigor can be prolonged indefinitely
in fish by destroying the central nervous system as soon as they are taken from the

page_text: water, gutting them, and keeping them at a low temperature,) and placed in a
preserving machine, in order-
1. To have all the germ laden, air, in and around the fish, and the gases from the
tissues as far as possible removed, and
2. To have the tissues thoroughly saturated with the preserving solution.
To effect this, the fish &c. are introduced into a van which, (by being placed on
rails) is run into the preserving machine. After the cover of the machine has been
fixed, by bolts the preserving fluid is forced from a cistern into the apparatus until
it reaches to the top the tap is then closed, and the air extracted, by means of an
ordinary air pump or other means.
The extraction of the air is continued for half an hour or longer the time
depending on the nature of the material under treatment.
An indicating tube is provided to show the escape of the gases.
When sufficiently exhausted the air pump is closed, and the tap from the cistern
opened. By the atmospheric pressure, the preserving liquid is driven into the
cavities previously filled with air or gases. The iap is again closed and a pressure of
from 5 to 8 atmospheres, applied in order to make certain that the tissues are
thoroughly saturated with the preservative. The pressure is applied for an hour in
some cases, but in other cases a quarter of an hour is sufficient. Finally the tap is
turned, and the solution allowed to pass back into the cistern and the apparatus
having been opened, the fish &c. are removed and packed either in common boxes or
barrels with or without preserving solution.
When the fish &c. only require to be kept for a few days it is only necessary to
use a very weak solution of common salt (say 24 per cent.) when to be kept longer,
it is necessary to add in addition 24 per cent. of boracic acid and in some cases it is
advantageous to add further a per cent. of nitre. When the fish &c. have to be
preserved for two or three weeks they should be placed in barrels, in a solution
containing 1 per cent. of salt, and 2 per cent. of boracic acid.
By this method of preservation the fish &c. treated, contain only a trace of the
salt &c. used while they retain almost unaltered their original appearance and taste
and no special arrangements are required for their conveyance from the fishing
stations to distant markets.
Dated this 3rd day of March 1887.
CARPMAEL & Co.,
Agents for the Applicant.

page_text: Improvements in Preserving Fish and other Matters and in
Apparatus for the same.
I, CARL ADOLF SAHLSTRÖM of Albert Quay, in the City of Aberdeen, Gentleman,
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:-
By extensive experiments it has been ascertained that there is a relation between
the disappearance of the "rigor mortis " of fish and other animals and the beginning
of putrefaction, and that the rate of the putrefactive process to a large extent
depends on the amount of gases and fluids present in the tissues. Further it has
been shown that even the earliest stages of putrefaction are associated with the
presence of Bacteria, and other minute organisms, and that when the invasion of
the tissues by Bacteria is prevented, not only is putrefaction delayed, but the "rigor"
or stiffening is maintained.
Hence in preserving fish, it is necessary to treat them before the rigor has passed
off, and either to prevent Bacteria reaching them, or to render the muscles &c.
incapable of providing the Bacteria with the nourishment necessary for their growth
and development.
Hitherto, common salt has been chiefly used for preserving fish.
When salt is used in the ordinary way it is necessary to use a 20 per cent.
solution. This strong solution, while it effectively prevents the growth of Bacteria,
so alters the tissues that they are no longer either so nourishing palatable or
digestible.
Sometimes boric (boracic) and other acids, are used, either alone or with salt and
other chemicals, all of which are more or less objectionable, when sufficient is used
to preserve the fish, even when they are kept under considerable pressure.
As the result of numerous chemical and other investigations I have devised the
following method of preserving which commends itself chiefly because by only
requiring the smallest amount of salt or other preservatives, the tissues are left
almost unaltered.
The fish &c. to be preserved are obtained before putrefaction has set in, or as soon
as possible after the rigor has disappeared, (the rigor can be prolonged indefinitely
in fish by destroying the central nervous system as soon as they are taken from the
water, gutting them, and keeping them at a low temperature) and placed in a
preserving machine in order-
1. To have all the gerin laden air, in and around the fish, and the gases from the
tissues as far as possible removed and
2. To have the tissues thoroughly saturated with the preserving solution.
in order that the said invention may be most fully understood and readily carried
into effect I will proceed to describe the drawings hereunto annexed.

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side elevation.
Figure 2 is an end elevation.
Figure 3 a plan of the apparatus devised for carrying out the invention.
In these Figures D is a strong vessel or receiver having at its top a dome D¹ and
a door D³ carried by hinges. EE are rails placed across and below the mouth of
the vessel D, on these is a truck F and on this truck a van V mounted on wheels so
that when the truck F is run in front of the vessel D the van can be run into the
vessel and the door be closed.
The operation of this apparatus is as follows:-
:-
The fish &c. are introduced into the van V which, (by being placed on rails) is
run into the preserving machine. After the cover of the machine has been fixed by
bolts the preserving fluid from the cistern C is forced into the apparatus until it
reaches up to the dome D¹ the tap is then closed, and the air extracted by means of
an ordinary air pump or other means.
The extraction of the air is continued for half an hour or longer, the time
depending on the nature of the material under treatment.
The escape of the gases is indicated by bubbles passing the glasses marked G.
When sufficiently exhausted the air pump is closed and the tap from the cistern
opened. By the atmospheric pressure, the preserving liquid is driven into the
cavities previously filled with air or gases. The tap is again closed and a pressure
of from 5 to 8 atmospheres applied in order to make certain that the tissues are
thoroughly saturated with the preservative. The pressure is applied for an hour in
some cases, but in other cases a quarter of an hour is sufficient.
Finally the tap T is turned, and the solution allowed to pass back into the
cistern and the apparatus having been opened, the fish &c. are removed, and
packed either in common boxes or barrels with or without preserving solution.
When the fish &c. only require to be kept for a few days it is only necessary to
use a very weak solution of common salt (say 24 per cent.) when to be kept longer,
it is necessary to add in addition 24 per cent of boracic acid and in some cases it is
advantageous to add further a per cent. of nitre. When the fish &c. have to be
preserved for two or three weeks they should be placed in barrrels, in a solution
containing 14 per cent. of salt, and 2 per cent. of boracic acid.
By this method of preservation the fish &c. treated, contain only a trace of the
salt &c. used while they retain almost unaltered, their original appearance and taste,
and no special arrangements are required for their conveyance from the fishing
stations to distant markets.
my
Having now particularly described and ascertained the nature of said invention
and in what manner the same is to be performed I declare that what I claim is :-
1. Removing the gases existing in the tissues by mechanical means and sub-
stituting a preservative liquid for the same.
2. The use by the aid of vacuum and pressure of a solution containing salt,
boracic acid and nitre for the purpose of preserving.
3. The combination of apparatus for carrying out the process consisting of an
openwork van capable of running upon rails with the preserving vessel for receiving
the same substantially as described.
4. The apparatus substantially as described and illustrated in the drawings.
T: 03nd dex of November 1887