Cold compress

“ In the first place, absolute rest, chiefly in a supine position, must be observed not only during the menstrual period, but for a few days previous to its commencement. If this does not restrain the flow, then cool and even cold compresses may be applied to the lower part of the abdomen and to the small of the back. In severe cases no harm will come from the use of an ice-compress, made by inclosing pounded ice between the folds of a towel. Great care must be taken to make the hands, arms, feet, and limbs thoroughly warm by the application of warm bottles and woolen blankets. ”

“ Cold compresses, either in the form of cloths wet with cold water or bladders filled with ice, can only produce a local fall of temperature, and therefore, except when applied to the head, can be of little service. ”

“ Now, if the cycle-pump heats our hands, it will be easily understood that the temperature of the compressors is very high. They are water-jacketed like the cylinders of a gas-engine, so that a circulating stream of cold water may absorb some of the heat. The compressed air is passed through spiral tubes winding through large tanks of water which fairly boils from the fierceness of the heat of compression. ”

“ A cubical compression of any elastic fluid or solid in an ordinary condition causes an evolution of heat; but, on the contrary, a cubical compression produces cold in any substance, solid or fluid, in such an abnormal state that it would contract if heated while kept under constant pressure. ”

“ Or again, if the laws of energy are true, it may be shown that, whenever a substance contracts when heated, it will become colder instead of hotter by compression. Now, we know that ice-cold water, or water just a little above its freezing point, contracts instead of expanding up to 4° C.; and Sir William Thomson has found, by experiment, that water at this temperature is cooled instead of heated by sudden compression. ”

“ Your observation is very natural; but consider that in a frost the atmosphere is so much colder than the earth, that all the caloric which it takes 158 from the freezing bodies is insufficient to raise its temperature above the freezing point; otherwise the frost must cease. But if the quantity of latent heat extricated does not destroy the frost, it serves to moderate the suddenness of the change of temperature of the atmosphere, at the commencement both of frost, and of a thaw. In the first instance, its extrication diminishes the severity of the cold ”

“ For if Air were forced by condensation into a less compass than it took up before, and then exposed to a very considerable degree of cold, it would remain quite inactive, without exerting such an effort as it usually makes against the compressing body. ”

“ Water and cast iron have about the same relative capacity for heat at equal volumes. In this water piston compressor we have only one cooling surface, which soon gets hot, while with a dry compressor, with water jacketed cylinders and heads, there are several cold metallic surfaces exposed on one side to the heat of compression, and on the other to a moving body of cold water. ”

“ The reason of this is, that we cannot feel warm till we have been cold, and vice versâ."
"Our bodies," resumed Fritz, "however much the thermometer descends, never mark less than thirty-five degrees above zero. In winter the skin shrinks, and becomes a bad conductor of heat from without; but, at the same time, does not allow so much gas and vapor to escape from within. In summer, on the contrary, the skin dilates and allows perspiration to form, a process that consumes a considerable amount of latent heat. ”

“ When a region of the skin which is endowed only with protopathic sensibility is stimulated with cold, the intensity of the cold sensation is roughly the same whether the temperature of the stimulating surface is zero or 20°C., i.e., whether it is the temperature of ice or about the temperature of a summer day. ”

“ We have here, then, two processes—one of evaporation, another of condensation; and these, by an express and admirable provision, have a constant tendency to limit each other's operations. Evaporation is increased by heat, but it produces cold in proportion to the rapidity with which it is carried on. Condensation is produced by cold, and at the same time heat is liberated. ”

“ Ah, but you forget that the quick expansion of a gaslike air produces cold. We shall regulate our temperature in that way. If it is becoming too warm inside, the new measure of condensed air will be quickly introduced into the partial vacuum, and [43] its sudden expansion will produce great cold, and freeze ice for us if we wish it. On the other hand, if the compartments are already cold, we shall allow the condensed air to enter very gradually, and its slow expansion will produce but little cold. ”

“ Most artificial ice is made by what is called the compressor system. It is called the compressor system because the ammonia with which che freezing is done is first compressed by means of powerful steam pumps. These pumps then force it through pipes over which cold water is running. This cold water bath still further condenses the gas to a liquid state, which drives out all the heat there is in it. The illustration shows how water is kept playing on the pipes containing the compressed ammonia. ”

“ But inside of those blankets your body is giving out heat waves, the air on the inside becomes warm, and you are comfortable. Suppose again that the blankets are not the right kind, they will not retain heat, and as a consequence you become cold. You sit up, replenish the fire and swear to yourself, but you don't know why you can't keep warm. You say the cold gets through your blankets and you firmly believe this. As a matter of fact it is the heat that gets through, not the cold. ”

“ The cold had become intense, a bitter piercing cold which strained and snapped at joist and beam and turned the slush of yesterday to flint. From the street below every sound broke sharp and metallic—the clatter of sabots, the rattle of shutters or the rare sound of a human voice. The air was heavy, weighted with the black cold as with a pall. To breathe was painful, to move an effort. ”

“ Many cases are recorded of similar stages of decomposition, which is an apparent spontaneous combustion, renewing the normal temperature of life, many times giving flushness to the cheeks, and thus appearing to have life renewed, notwithstanding the body had been cold for many hours previous to this phenomenon taking place, the result of a peculiar chemical action. ”

“ The excessive dryness of the air at Davos has probably but little special influence upon the sensation of heat and cold, because the maximum proportion of aqueous vapor present in air near the freezing-point is everywhere small, and the specific heats of equal volumes of air and aqueous vapor are not widely different. ”

“ Thus discrimination of temperature is similar to discrimination of touch, which depends on more or less sudden change of pressure. The term cold means, physiologically, the sensation we experience when heat is abstracted, and the term heat, the sensation felt when heat is added to the part. Thus we are led to consider that the skin contains at least two kinds of specific terminal organs for sensations of touch and temperature, and two sets of nerve fibres which carry the nervous impulses to the brain. ”

“ In many we see this to be the case in ordinary winters; for some, severe frosts are requisite; others freeze only with the most intense artificial colds; and some have hitherto resisted all our endeavours; yet the number of these last is few, and they will probably cease to be exceptions as our means of producing cold become enlarged.
(358.) A similar analogy leads us to conclude that all aëriform fluids are merely liquids kept in the state of vapour by heat. Many of them have been actually condensed into the liquid state by cold accompanied with violent pressure ”

“ The highest isothermal results are obtained by the injection of water into the cylinders, since it is plain that the injection of cold water, in the shape of a finely divided spray, directly into the air during compression will lower the temperature to a greater degree than simply to surround the cylinder and parts by water jackets which is the means of cooling adopted with dry compressors. ”

“ The expansion of the compressed gas freezes the moisture on the tube.
One reason why it is always cold high up in the air. Even on hot summer days aviators who fly high suffer from the cold. You might think that they would get warmer as they went up nearer the sun; one reason that they get colder instead is this:
As you saw in the last experiment, a gas that expands gets very cold. Air is a kind of gas. And whenever air rises to where there is not so much air crowding [pg 96] down on it from above, it expands. So the air that rises high and expands gets very cold. ”

“ I will notice one of the principal causes having a tendency to prevent the perfect uniformity of chemical action, between the iodine and silver; hydrogen, or the moisture in the atmosphere, makes a very perceptible barrier. This moisture may arise as the result of the cold, from a want of friction in the buffing of the plate, which, coming in contact with the warmer air, as a writer on this subject says:
“It is well known that as often as bodies, when cold, are exposed to a warmer air, the humidity contained in them is condensed. ”

“ A. Metal is an excellent conductor; and, therefore, becomes rapidly heated. For the same reason it becomes rapidly cold, when it comes in contact with a body colder than itself.
Q. Why does a pump-handle feel intensely cold in winter?
A. As metal is an excellent conductor, when the hot hand touches the cold pump-handle, the heat passes rapidly from the hand into the iron; and this rapid loss of heat produces a sensation of intense coldness. ”

“ A thermometer, had they carried one, would probably have registered from ten to twenty below zero of Fahrenheit. This, however, was so familiar to them that they rather liked the change, and heaped up fresh logs on the roaring fire to counteract the cold; but when a breeze sprang up and began to blow hard, they did not enjoy it so much, and when the breeze increased to a gale, it became serious; for one cannot face intense cold during a gale without the risk of being frost-bitten. ”

“ Let a glass tube be filled three parts full and it will descend in proportion as the cold increases, but some time before congelation it will ascend [89] above the point of three fourths of the height of the tube, and increase still more considerably by being frozen. But if the tube be well stopped, and perfectly at rest, the water will continue to descend, and will not freeze, although the degree of cold be six, eight, or ten degrees below the freezing point; congelation, therefore, presents, in an inverted manner, the same phenomena as inflammation. ”

“ The cold packs and compresses, on the other hand, have a directly cooling effect upon the seat of inflammation and in accordance with the Law of Action and Reaction their secondary, lasting effect consists in drawing the blood from the congested and heated interior to the surface, thus relaxing the pores of the skin and promoting the radiation of heat and the elimination of impurities. ”

“ If a box containing a mixture of ice and salt is placed round the top of a long cylindrical glass containing water at a temperature of 60° Fahr., the intense cold of the freezing mixture, which is zero—that is to say, 32° below the freezing point of water—very soon reduces the temperature of the water contained in the glass, and as it becomes colder it contracts, is rendered heavier, and sinks to the bottom of the vessel, and its place is taken by other and warmer water. ”

“ The difference of which we now speak is common also to the nature of cold, in which the contracting motion is restrained by the resistance of expansion, as in heat the expansive motion is restrained by the resistance of contraction. Whether, therefore, the particles of matter penetrate inward or outward, the reasoning is the same, though the power be very different, because we have nothing on earth which is intensely cold. ”

“ Heat, although it may inconvenience the experimenters and the medium, appears to exercise a favourable influence on the emission of the force. On the contrary, cold is an element of non-success. Of course, I am speaking of the temperature of the room. I would advise operating in a temperature of from 20 to 25 degrees centigrade. It [34] is decidedly necessary to avoid having cold hands and feet.
In winter the seance-room should be thoroughly warmed and the fire allowed to go out before the sitting, in case luminous phenomena should be forthcoming. ”

“ The mercury by this time had fallen to 38° below zero. We were surprised and delighted to find that we stood the cold so easily, and prided ourselves not a little on our powers of endurance. Our feet gradually became benumbed, but, by walking up the hills, we prevented the circulation from coming to a stand-still.
The cold, however, played some grotesque pranks with us. My beard, moustache, cap, and fur collar were soon one undivided lump of ice. Our eyelashes became snow-white [Pg 52] and heavy with frost, and it required constant motion to keep them from freezing together. ”

“ Internal Refrigerants. There are certain saline substances which, by undergoing a rapid solution, and acquiring an increased capacity for caloric, produce a diminution of temperature, and if this takes place in the stomach, the sensation of cold which it will produce is equivalent to a partial abstraction of stimulus; which, being extended by sympathy to the heart, occasions a transient reduction in the force of the circulation, and by this, or by a similar sympathetic affection, causes a sensation of cold over the whole body ”