Improvements in the Preservation of Meat, and in Appara tus therefor.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Preservation of Meat, and in Appara tus
therefor.
I, AUGUST ZIMMERMANN, of 9 and 10, St. Mary at Hill, in the City of London,
Merchant, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by The Chemische Fabrik auf Actien vorm. E.
Schering, of 170, Müllerstrasse, Berlin, in the Empire of Germany,) to be as
follows:-
Up to the present time no simple and sure method has been found of pre-
serving fresh meat by means of formic aldehyde in such a manner that its pro-
perties and appearance are unaltered. The most obvious method of using formic
aldehyde was by dipping the meat into a dilute solution. By this method the meat
however can only be protected from corruption for quite a short time. This
method besides cannot be used on a large scale as it is too troublesome and un-
certain.
The problem of preserving meat by means of formic aldehyde can only be solved
by the use of gaseous formic aldehyde and this only under most definite condi-
tions. First the amount of gaseous formic aldehyde evolved must be exactly
determinable in order to prevent any useless and prejudicial excess.
For pre-
serving meat in especial, only exceedingly small quantities of formic aldehyde
are necessary, because fresh slaughtered meat is entirely free from germs and
putrefaction which emanates only from putrefaction bacteria collecting on the
surface of the meat. Superficial sterilization of the meat is only therefore neces-
sary. The use of an excess of formic aldehyde, irrespective of the higher cost of
preserving, has great disadvantages, in that the meat becomes strongly dis-
coloured. It is not practicable to employ the formic aldehyde lamp at present
in use, which produces formic aldehyde by incomplete combustion of methyl
alcohol, as this lamp sometimes produces more and sometimes less formic alde-
hyde, and thus causes sometimes too complete preservation and at other times
incomplete preservation.
The disinfecting apparatus described in the British Patent No. 26667 in the
year 1896, in which paraformaldehyde pastilles are used each producing a gram
of 100% gaseous formic aldehyde may for example be used for exactly dosing
the quantities of formic aldehyde.
According to this invention, meat may be preserved by proceeding in the
following manner.
The meat is hung up in a receptacle, somewhat of the form of an ice safe, and
the formic aldehyde producer of the type indicated having the proper proportion
of pastilles is put to work in the safe and the latter shut air tight. The small
spirit lamp of the apparatus burns quietly out, after the oxygen present in the
safe has been used up. After the formic aldehyde vapour has acted for a short
time the meat is sterilized. It completely suffices for this purpose to gasify
11%, to at most 2 paraformaldehyde pastilles per cubic metre capacity of the safe.
In order to preserve meat for a long time the treatment as described is in-
sufficient. For this the safe must be ventilated by sterile air in order to prevent

page_text: the meat after a time becoming cupboardy in consequence of the absence of
fresh air.
For this purpose a ventilation valve is provided, which is opened by means of
a slide, and admitting air through filters of cotton wool. Sterile air now flows
through the ventilation holes into the safe, and can escape through an outlet
pipe also provided with a slide.
The meat thus hangs in a germ free and ventilated space and is absolutely
free from bacteria. By this all conditions for keeping meat fresh are fulfilled.
Putrefaction of the meat is precluded, because by means of the formic aldehyde
vapours, the putrefaction bacteria are killed, and further no so-called acid stink-
ing fermentation can be set up, because fresh germ free air circulates in the safe.
The safe is best put in a moderately cool odourless place.
If the safe be opened for the purpose of withdrawing the meat, the bacteria
newly entered in this manner must be destroyed by the renewed action of the
formic aldehyde gas producer. This however need not be done directly after each
opening, it is. sufficient to sterilize the safe and its contents every three days.
It is even advantageous especially when there is no wind, to open the safe door
daily once for about an hour to create a draught.
This method of preserving meat possesses the following great advantages over
others:
1. The value of the meat in nourishment and taste is not lessened whilst for
example salt meat is under all circumstances of less value because it has under-
gone a considerable loss in nutritious matter.
2. The meat can be used for all purposes because the taste of fresh meat re-
mains completely preserved. The appearance of the meat also remains nearly
unaltered; it is never discoloured deep down but at most only slightly on the
surface.
3. Meat treated by this method is not in the slightest degree injurious to
health because a minimal amount only of formic aldehyde adheres to the meat
and that only on the surface, in any case not in greater quantities than is con-
tained in smoked meat. The formic aldehyde contained in smoked meat
originates from the wood smoke employed.
4. The method is exceedingly simple, cleanly and cheap. For a safe of 1 cubic
metre capacity two paraformaldehyde pastilles are at most necessary. Pre-
servation by heat (tinued meats) is too dear and can only be used in exceptional
cases. Store chambers cooled by machinery, only pay for large meat companies.
Preservation by means of ice is also very costly.
5. The meat can be retained fresh for as long as the butcher, dealer and con-
sumer wishes.
6. The meat remains, after withdrawal from the preserving safe, fresh for a
much longer time than meat preserved by cold air or ice.
7. Meat treated with formic aldehyde well bears changes in temperature and
atmosphere and also transport.
8. The method can be put into practice everywhere and by everybody.
101
1000
CARPMAEL & Co.,
Agents for the Applicant.
Improvements in the Preservation of Meat, and in Apparatus
therefor.
T, AUGUST ZIMMERMANN, of 9 and 10, St. Mary at Hill, in the City of London,
Merchant, do hereby declare the nature of this invention (which has been com

page_text: municated to me from abroad by The Chemische Fabrik auf Actien vorm. E.
Schering, of 170, Müllerstrasse, Berlin, in the Empire of Germany,) and in what
manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
Up to the present time no simple and sure method has been found of pre-
serving fresh meat by means of formic aldehyde in such a manner that its pro-
perties and appearance are unaltered. The most obvious method of using formie
aldehyde was by dipping the meat into a dilute solution. By this method the meat
however can only be protected from corruption for quite a short time. This
method besides cannot be used on a large scale as it is too troublesome and un-
certain.
4
The problem of preserving meat by means of formic aldehyde can only be solved
by the use of gaseous formic aldehyde and this only under most definite condi-
tions. First the amount of gaseous formic aldehyde evolved must be exactly
determinable in order to prevent any useless and prejudicial excess
For pre-
serving meat in especial, only exceedingly small quantities of formic aldehyde
are necessary, because fresh slaughtered meat is entirely free from germs and
putrefaction which emanates only from putrefaction bacteria collecting on the
surface of the meat. Superficial sterilization of the meat is only therefore neces-
sary. The use of an excess of formic aldehyde, irrespective of the higher cost of
preserving, has great disadvantages, in that the meat becomes strongly dis-
coloured. It is not practicable to employ the formic aldehyde lamp at present
in use, which produces formic aldehyde by incomplete combustion of methyl
alcohol, as this lamp sometimes produces more and sometimes less formic alde-
hyde, and thus causes sometimes too complete preservation and at other times
incomplete preservation.
The disinfecting apparatus described in the British Patent No. 26667 in the
year 1896 in which paraformaldehyde pastilles are used each producing a gram
of 100% gaseous formic aldehyde may for example be used for exactly dosing
the quantities of formic aldehyde.
According to this invention, meat may be preserved by proceeding in the
following manner.
The meat is hung up in a receptacle somewhat of the form of an ice safe, and
the formic aldehyde producer of the type indicated having the proper proportion
of pastilles is. put to work in the safe and the latter shut air tight. The small
spirit lamp of the apparatus burns quietly out, after the oxygen present in the
safe has been used up. After the formic aldehyde vapour has acted for a short
time the meat is sterilized. It completely suffices for this purpose to gasify
11, to at most 2 paraform aldehyde pastilles per cubic metre capacity of the safe.
In order to preserve meat for a long time the treatment as described is in-
sufficient. For this the safe must be ventilated by sterile air in order to prevent
the meat after a time becoming cupboardy in consequence of the absence of
fresh air.
For this purpose a ventilation valve is provided which is opened, after about
7 hours, by means of a slide, and admitting air through filters of cotton wool.
Sterile air now flows through the ventilation holes into the safe, and can escape
through an outlet pipe also provided with a slide.
The meat thus hangs in a germ free and ventilated space and is absolutely
free from bacteria. By this all conditions for keeping meat fresh are fulfilled.
Putrefaction of the meat is precluded, because by means of the formic aldehyde
vapours, the putrefaction bacteria are killed, and further no so-called acid stink-
ing fermentation can be set up, because fresh germ free air circulates in the safe.
The safe is best put in a moderately cool odourless place.
If the safe be opened for the purpose of withdrawing the meat, the bacteria
newly entered in this manner must be destroyed by the renewed action of the
formic aldehyde gas producer. This however need not be done directly after each
opening, it is sufficient to sterilize the safe and its contents every three days,

page_text: Figure 1 is a perspective view of the apparatus. Figures 2 and 3 are local
vertical and horizontal sections.
a is the safe preferably made with double walls with non-conducting material a¹
between them. 6 is chimney closed by a damper 61. e is the door with an open-
ing in it having wire gauze el on each side with cotton wool hetween. dis a
slide covering the opening. e are similar openings also provided with cotton wool
filters and covered by a slide e¹.
This method of preserving meat possesses the following great advantages over
others:
1. The value of the meat in nourishment and taste is not lessened whilst for
example salt meat is under all circumstances of less value because it has under-
gone a considerable loss in nutritious matter.
"
2. The meat can be used for all purposes because the taste of fresh meat re-
mains completely preserved. The appearance of the meat also remains nearly
unaltered; it is never discoloured deep down but at most only slightly on the
surface.
3. Meat treated by this method is not in the slightest degree injurious to
health because a minimal amount only of formic aldehyde adheres to the meat
and that only on the surface. in any case not in greater quantities than is con-
tained in smoked. meat. The formic aldehyde contained in smoked meat
originates from the wood smoke employed.
4. The method is exceedingly simple, cleanly and cheap. For a safe of 1 cubic
metre capacity two paraformaldehyde pastilles are at most necessary. Pre-
servation by heat (tinned meats) is too dear and can only be used in exceptional
cases. Store chambers cooled by machinery, only pay for large meat companies.
Preservation by means of ice is also very costly.
5. The meat can be retained fresh for as long as the butcher, dealer and con-
sumer wishes.
6. The meat remains, after withdrawal from the preserving safe, fresh for a
much longer time than meat preserved by cold air or ice.
7. Meat treated with formic aldehyde well bears changes in temperature and
atmosphere and also transport.
8. The method can be put into practice everywhere and by everybody.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
1. The preservation of meat by first exposing it to gaseous formic aldehyde in
a closed chamber and then ventilating the chamber with germ-free air.
2. The process and apparatus for the preservation of meat substantially as
described and illustrated in the drawings.
Dated this 12th day of April 1899