Year: 1887

page_text: Date of Application, 14th Mar., 1887
Complete Left, 28th Nov.. 1887
Complete Accepted, 30th Dec., 1887
I, GEORGE DOWNING, of
the Republic of France.
Quality Court, Chancery Lane, in the County of
Middlesex, Patent Agent, do hereby declare the nature of the said invention to be as
follows:-
apparatus.
The object of my invention is to manufacture refrigerating substances or materials,
in a convenient form, so that the same may be kept ready for use in households and
factories: in medical practice; and all other cases where the production of artificial
cold may
be required, in substitution of ordinary ice and other refrigerating
In carrying out my Invention, I use any suitable non-conducting, absorbent, fibrous
material, such as flock wool, cotton wadding, tissues, cotton felt, tow, jute, China
grass, and analogous substances, and cause the same to absorb, by pressure or other-
wise, a mixture or mixtures of frigorific salts, such as Nitrate of ammonia (N. H.
4 NO 3), Sal ammoniac (N. H. 4 Cl), Nitrate of potash (K. N. O. 3) Sulphate of soda
(Na 2 S. O. 4) Sulphocyanide of potassium, and the like.
In order to obtain an intimate and uniform combination of the crystallised salts,
with the fibres of the absorbent material, there are two general modes of proceeding
which will now be described.
First. The frigorific salts or crystals are produced within the fibres of the absorbent
material, after the latter has been impregnated by immersion in a solution of the salts
in water.
Secondly. One, or several layers, of absorbent material, of suitable form and
dimensions or thickness, is or are impregnated with saturated solutions in water, of
the said frigorific salts, or of a mixture of the same; due account being taken of the
hygroscopic capillarity of the material: the water is subsequently evaporated by heat.
The crystallisation of the salts resulting therefrom, assumes the form of a crust and

page_text: in order to obtain a uniform distribution of the fine crystals, within the hygroscopic
material, recourse must be had to mechanical means. such for instance as pressing
between rollers, or to the fulling and shaking of the fabrics in spaces filled with warm
and very dry air.
Instead of a solution in water as above described, a solution in alcohol may be
substituted in some cases.
In the production of frigorific or refrigerant mixtures, according to the first.
method described, and when for instance simple compressers or bolsters (such as
bandages placed upon the forehead and other similar handages) are used as refrigerants,
a substance known as sphagnum may be used, as the absorbent material. This
substance can be more easily treated than other substances, owing to its peculiar
nature which is very nearly that of felt, while it is more resistant during the various
manipulations to which it is subjected than hygroscopic cotton wadding, tow, jute,
and China grass. This "sphagnum" felt as well as other absorbent materials, should
be used in pieces of uniform size and weight. It is preferable to cut them to the
required shape previously to their impregnation. Supposing, for example, that a
saturated solution of nitrate of ammonia he employed, such solution is obtained by
neutralizing nitric acid with carbonate of ammonia, in large glass vessels or jars. The
thoroughly neutral bath obtained in this manner is subsequently heated over a slow
fire, and preferably in vaporizers, until the precise moment when a crust of salt
appears at the edges of the vessel or upon the immersed object. This is now the
proper time for proceeding to the impregnating operation, as by further heating, the
solution would again become acidified. In order to be able to calculate in advance
the quantities required, it is necessary to obtain a knowledge by experiment or other-
wise, of the absorbent qualities of the various hygroscopic substances, as authorities
differ very much upon the subject. This is also necessary for impregnating pieces
of felt or of wadding with an approximately constant quantity of salt for each piece.
and such knowledge further serves as a basis for the calenlation of the quantity of
water required for the production of the desired refrigerant effect. The felt or the
cotton wadding is now immersed in the original mixture which is maintained at an
equal temperature, until it is thoroughly impregnated. The duration of this operation
is ascertained by experiment: "sphagnum" for instance absorbs only half the
quantity of liquid compared with that absorbed by hygroscopic cotton of the best
quality. On issuing from the bath the pieces of felt or of wadding, are subjected to
a slight but uniform pressure, in order to enable them all to contain exactly, or at
least approximately, the same quantity of salt. For this operation a polished board
of hard wood is used (the size of the board being similar to that of each piece to be
operated upon) provided upon its upper surface with a sheet of lead to weight the
same, and being further supplied with a handle. This board is then placed without
additional pressure upon the thoroughly wetted compress or piece of material, after
which it is withdrawn therefrom. It is preferable to effect at once the removal of
the excess of liquor from the table (consisting of baked earthenware, of slate or of
other suitable kind of stone or earth) upon which crystallisation is caused to take place.
The drying of the compresses is effected at a temperature of about 50° C. and
preferably in an apparatus provided with slides and arranged in the manner of a stove
or oven. While crystallisation is taking place in the intertices of the pieces of felt
or wadding, it is necessary to turn them over at least once. By these means a
thoroughly uniform distribution of the crystals is obtained, as otherwise crystals
would form only upon the surface. As soon as the pieces of felt or wadding are
completely dried, and impregnated with crystals, they are deposited in ordinary
hygroscopic wadding, and are wrapped up in gauze, or in hygroscopic fabric. The
application of these wrappers is absolutely necessary to prevent the displacement of
the crystals during the mechanical manipulations which follow. Although it is not
possible that large crystals should form within the fibres of felt or wadding, it is
however a matter of great importance with reference to the refrigerant effect required,
that the salts should be reduced to the finest powder possible. This result may be
obtained either by hand, with the aid of beaters or by machinery as, for example, by

page_text: means of a fulling machine: care should also be taken that the compresses or bandages
thus formed should not absorb moisture. It is preferable as a precautionary measure
to subject them again to the action of heat before completing the process upon the
table. The latter apparatus effects the uniform distribution of the finely powdered
salts through the fibres of the whole bandage or compress.
An objection may be made to the effect that the whole of the herein before described
process may be dispensed with, if felt or wadding were simply treated in the fulling
machine with finely powdered refrigerating salts. This may be possible, but it is an
established fact that refrigerating salts which are thoroughly dry cannot be uniformly
distributed in wadding, while it is incapable of being distributed in felt. The fibres
must be prepared by means of a moist impregnation, in order to promote the adhesion
of the salts. It may be moreover remarked that nitrate of ammonia obtained (for
instance) in a state of freshness by a crystallisation in the fibres is much more
efficacious than that which is purchased in the usual way from tradesmen or others.
Ii may also be mentioned that the possibility of producing in the course of the
process refrigerating salts in the fibres of the felt or wadding is a very essential
point.
The refrigerating action is produced by the simple addition of water, that is to
say, by wetting die bandages or compresses in the manner hereinafter described.
The refrigerant action of the products under consideration (compresses and the like)
may be considerably increased by adding thereto a quantity of crystallized soda equal
to the quantity of nitrate of ammonia which they contain. This can be effected in
the following manner. At the time of removing the felt or the wadding from the
bath of nitrate of ammonia, the compresses are simply sprinkled over, on both sides,
with crystallised soda, and, thus treated, are packed into cotton wadding, and after-
wards wrapped in cotton wadding or gauze. By now subjecting the compresses to
the drying process and mechanical treatment above described, the required union of
the two refrigerating salts which effects the lowering of the temperature considerably
below zero is securel. Besides the above named salts, there are mixtures by means
of which analogous though much feebler effects can be obtained. In order to produce
refrigerating effects, or effects from substitutes for ice, the hygroscopic fabrics are
according to the process described under the second process subjected to a drying
process, and a mechanical treatment, after having been previously impregnated with a
saturated solution (in water) of refrigerant salts. If this impregnation is effected
with a solution in water, the drying process is extremely slow and difficult, and the
rapid escape of the moisture would be increased if effected by means of mechanical
apparatus (with a motor).
As above described an alcoholic solution may be used in some cases. For instance
by impregnating felt and cotton wadding with an alcoholic solution of sulphocyanide
of potassium, this impregnation being followed by the necessary drying process and
mechanical treatment, in order to cause the crystals to thoroughly permeate the fabric,
very good results are obtained, which however are more costly than those before
mentioned. The refrigerant effect, obtained by making use of nitrate of ammonia, is
always of greater value than others, since, after it has been in use. it is always capable
of being used again, provided it has been previously dried. The crystals of these
salts are formed anew in the hygroscopic material, after the evaporation of the water,
but the drying process must be facilitated as much as possible.
The application of the various refrigerant remedies is made either by wetting one
side only of the compress, or by immersing one side only of the same in a certain
quantity of water. In the last case the refrigerant products act in a similar manner
to the wicks of lamps, that is to say, they imbibe the water, and a gradually increasing
cooling action takes place. The refrigerant action of the various frigorific remedies
depends upon their being preserved in a thoroughly dry state, also upon the rapidity
with which their uniform moistening takes place, and upon the quickness of the
subsequent manipulation. The quantity of water necessary for the refrigerant
products, to produce a frigorific action, varies according to the various refrigerant
salts produced. The refrigerant remedies prepared for instance with pure nitrate of

page_text: ammonia, or with a mixture of this salt with soda, require a quantity of water equal
to that of the salts which they contain. For each 3 parts of sulphocyanide of
potassium 2 parts of water are required.
The refrigerant products prepared with pure nitrate of ammonia lower the tempe-
rature to 3° C. below zero and the products prepared with a mixture of nitrate of
ammonia and soda lower the temperature to 8° C. below zero, while the products
repared with sulphocyanide of potassium bring the temperature down to 10° C.
elow zero.
By employing large quantities of refrigerant salts in an ice bag, and
by adding a corresponding quantity of water, a more intense cold can be produced
than by using small quantities of the same salts which are uniformly distributed in
cotton wadding, in gauze, or in tissues; but even in the last cases, the effect obtained
is very great, and suffices in most of its applications.
The thoroughly uniform action upon the whole surface of the part of the body to
which this refrigerant is applied, and its very easy and prompt use even in the inner
cavities of the body, where ice could not be applied without great difficulty, is
very advantageous; also that a perfectly dry cooling effect can be produced by using
a layer of impermeable fabric; and lastly may be mentioned the advantage of being
able, in certain cases, to repeat the use of the refrigerant remedies (compresses and
the like).

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Refrigerating Materials.
A communication from abroad by HENRY THEOPHILI BAESCHLIN, of Montpellier, in
the Republic of France.
1. GEORGE DOWNING, of S Quality Court, Chancery Lane in the County of
Middlesex, Patent Agent, do hereby declare the nature of my said invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
The object of my invention is to manufacture refrigerating substances or materials
in a convenient form, so that the same may be kept ready for use in households and
factories in Medical Practice, and all other cases where the production of artificial
cold may be required, in substitution of ordinary ice, and other Refrigerating means
and appliances.
In carrying out my invention, I use any suitable, non-conducting, absorbent,
fibrous material, such as flock, wool, cotton, wadding tissues, cotton-felt, tow, jute,
china grass and analogous substances, and cause the same to absorb, by pressure or
otherwise, a mixture or mixtures of frigorific salts, such as Nitrate of Ammonia
(NH 4 NO 3) Sal-ammoniae (N. H 4 Cl) Nitrate of Potash (K. NO 3) Sulphate of
Soda (Na 2 S. 0 4) Sulpho Cyanide of Potassium, and the like.
In order to obtain an intimate and uniform combination of the crystallized salts,
with the fibres of the absorbent material, there are two general modes of proceeding,
which will now be described.
First. The frigorific salts or crystals are produced within the fibres of the absorbent
material, after the latter has been impregnated by immersion in a solution of the
salts in water.
Secondly. One or several layers of absorbent material, of suitable form, or
dimensions, and thickness, is or are impregnated with saturated solutions in water of
the said frigorific salts, or of a mixture of the same, due account being taken of the
hygroscopic capillarity of the materials. The water is subsequently evaporated by heat,
the salt deposit resulting therefrom assumes the form of a crust; and in order to
obtain a uniform distribution of the fine crystals, within the hygroscopic materials,
recourse must be had to mechanical means such for instance as pressing between
rollers, or to the fulling and shaking of the fabrics in spaces filled with warm and very
dry air.
Instead of a solution in water, as above described, a solution in alcohol may be
substituted in some cases.
In the production of frigorific or refrigerant mixtures, according to the first
mentioned method, and when, for instance, simple compressors or bolsters (such as
bandages placed upon the forehead, and otherwise) are used as refrigerants, a substance
known as sphagnum may be used as the absorbent material.
"

page_text: This substance can be more easily treated than other substances, owing to its
peculiar nature, which is very nearly that of felt, while it is more resistant, during
the various manipulations to which it is subjected than hygroscopic cotton,
wadding, tow, jute, and China grass.
This Sphagnum felt, as well as other absorbent materials, should be used in pieces
of uniform size and weight.
It is preferable to cut the materials to the required shapes, previously to their
impregnation.
Supposing for example that a saturated solution of nitrate of ammonia be employed,
such solution is obtained by neutralising nitric acid with carbonate of ammonia, in
large glass vessels or jars.
The thoroughly neutral bath obtained in this manner, is subsequently heated over
a small fire, and preferably in vaporizers, until the precise moment when a crust of
salt appears at the edges of the vessel, or upon the immersed object.
This is now the proper time for proceeding to the impregnating operation, as by
further heating, the solution would again become acidified.
In order to be able to calculate beforehand the probable quantities required, it is
necessary to ascertain by experiment or otherwise, the absorbent qualities of the
various hygroscopic substances, as authorities differ very much upon the subject. This
is also necessary for impregnating pieces of felt, or of wadding, with an approximately
constant quantity of salt for each piece, and such knowledge further serves as a basis
for the calculation of the quantity of water required, for the production of the desired
refrigerant effect. The felt, or the cotton wadding, is now immersed in the original
mixture, which is maintained at an equal temperature until it is thoroughly
impregnated. The duration of this operation is ascertained by experiment;
sphagnum," for instance, absorbs only half the quantity of liquid, compared with
that absorbed by hygroscopic cotton, of the best quality. On issuing from the bath,
the pieces of felt or of wadding are subjected to a slight, but uniform pressure. in
order to enable them all to contain exactly, or at least approximately, the same quantity
of salt. For this operation, a polished board of hard wood is used (the size of the
board being similar to that of each piece to be operated upon) provided upon its upper
surface with a sheet of lead to impart weight to the same, and being further supplied
with a handle. This Board is then placed without additional pressure, upon the
thoroughly wetted compress, or piece of material, after which it is withdrawn there-
from. It is preferable to effect at once the removal of the excess of liquor from the
table (consisting of baked earthenware, state, or other suitable kind of stone or
earthenware) upon which crystallization is caused to take place. The drying of the
compresses is effected at a temperature of about 50° cent. and preferably in an
apparatus provided with slides, and arranged in the manner of a stove or oven. While
crystallization is taking place in the interstices of the pieces of felt or wadding, it is
necessary to turn them over at least once. By these means a thoroughly uniform
distribution of the crystals is obtained, as otherwise crystals would form only upon
the surface. As soon as the pieces of felt or wadding are completely dry, and
impregnated with crystals, they are deposited in ordinary hygroscopic wadding, and
are wrapped up in gauze, or in hygroscopie fabric. The application of these wrappers
is absolutely necessary, to prevent the displacement of the crystals during the
mechanical manipulations which follow. Although it is not possible that large
crystals should form within the fibres of felt or wadding, it is however a matter of great
importance, with reference to the refrigerant effect required, that the salts should be
reduced to the finest powder possible. This result may be obtained either by hand, with
the aid of heaters, or by machinery, as, for example, by means of a fulling machine:
care should also be taken that the compresses or bandages thus formed, should not
absorb moisture. It is preferable as a precautionary measure to subject them again
to the action of heat, before completing the process upon the table. The latter
apparatus effects the uniform distribution of the finely powdered salts, through the
fibres of the whole bandage or compress.
An objection may be made to the effect that the whole of the hereinbefore

page_text: described process may be dispensed with, if felt or wadding were simply treated in the
fulling machine with finely powdered refrigerating salts. This may be possible, but
it is an established fact, that refrigerating salts, which are thoroughly dry, cannot be
uniformly distributed in wadding, while it is incapable of being distributed in felt.
The fibres must be prepared by means of moist impregnation, in order to promote the
adhesion of the salts. It may be, moreover, remarked that nitrate of ammonia
obtained (for instance) in a state of freshness by a crystallisation in the fibres, is
much more efficacious than that which is purchased in the usual way from Tradesmen
and others.
It may also be mentioned that the possibility of producing, in the course of the
process, refrigerating salts in the fibres of the felt or wadding, is a very essential
point.
The refrigeration action is produced by the simple addition of water, that is to say,
by wetting the bandages or compresses in the manner hereinafter described.
The refrigerant action of the products under consideration (compresses and the
like) may be considerably increased by adding thereto a quantity of crystallised soda
equal to the quantity of nitrate of ammonia which they contain. This can be effected
in the following manner. At the time of removing the felt or wadding, from the bath
of nitrate of ammonia, the compresses are simply sprinkled over on both sides with
crystallised soda, and, thus treated, are packed into cotton wadding and afterwards
wrapped in cotton wadding or gauze. By now subjecting the compresses to the
drying process, and mechanical treatment above described, the required union of the
two refrigerating salts, which effects the lowering of the temperature, considerably
below zero, is secured. Besides the above named salts, there are mixtures, by means
of which analogous, though much feebler, effects can be obtained. In order to produce
refrigerating effects, or effects from substitutes for ice, the hygroscopic fabrics are,
according to the process described under the second process, subjected to a drying
process, and a mechanical treatment, after having been previously impregnated with a
saturated solution (in water) of refrigerant salts. If this impregnation is effected with
a solution in water, the drying process is extremely slow and difficult, and the rapid
escape of the moisture would be increased if effected by means of mechanical apparatus
(with a motor).
As above described, an alcoholic solution may be used in some cases; for instance.
by impregnating felt and cotton wadding with an alcoholic solution of sulphocyanide
of potassium this impregnation being followed by the necessary drying process and
mechanical treatment, in order to cause the crystals to thoroughly permeate the
fabric, good results are obtained, which, however, are more costly than those before
mentioned. The refrigerant effect, obtained by making use of nitrate of ammonia, is
of greater value than others, since, after it has been in use, it is always capable of
being used again, provided it has been previously dried. The crystals of these salts
are formed anew in the hygroscopic material, after the evaporation of the water. by
the drying process, which process should be facilitated as much as possible.
The application of the various refrigerant remedies, is made either by wetting one
side only of the compress, or by immersing one side only of the same, in a certain
quantity of water; in the last case the refrigerant products act in a similar manner to
the wicks of lamp, that is to say, they imbibe the water, and a gradually increasing
cooling action takes place. The refrigerant action of the various frigorific remedies
depend upon their being preserved in a thoroughly dry state, also upon the rapidity
with which their uniform moistening takes place, and upon the quickness of the
subsequent manipulation. The quantity of water necessary for the refrigerant pro-
ducts to produce a frigorific action, varies according to the character of the refrigerant
salts produced. The refrigerant remedies prepared, for instance, with pure nitrate of
ammonia, or with a mixture of this salt with soda, require a quantity of water equal
to that of the salts which they contain. For each 3 parts of sulphocyanide of
potassium, 2 parts of water are required.
The refrigerant products prepared with pure nitrate of ammonia, lower the
temperature to 30 cent. below zero; and the products prepared with a mixture of

page_text: while
nitrate of ammonia and soda, lower the temperature to 8° cent. below zero;
the products prepared with sulphocyanide of potassium, bring the temperature down
to 10° cent. below zero. By employing large quantities, of refrigerant salts in an ice
bag, and by adding a corresponding quantity of water, a more intense cold can be
produced, than by using small quantities of the same salis which are uniformly
distributed in cotion wadding, in gauze, or in tissues; but even in the latter cases,
the effect obtained is very great, and suffices in most of its applications.
The thoroughly uniform action upon the whole surface of the part of the body to
which this refrigerant is applied, and its very easy and prompt use, even in the inner
cavities of the body, where ice could not be applied without great difficulty, is very
advantageous also a perfecily dry cooling effect can be produced by using a layer
of impermeable fabric. And lastly may be mentioned the advantage of being able,
in certain cases, to repeat the use of the refrigerant remelies (compresses) and the
like.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
1. The manufacture and use of refrigerating appliances, consisting of non-
conducting, absorbent fibrous materials, impregnated with various frigorific salts,
crystallized, compressed and otherwise prepared ready for immediate use, subsequently
as hereinbefore described.
2. The combination of absorbent materials and frigorific salts, together forming my
improvements in the manufacture of refrigerating materials, substantially as herein-
before described.