Absorbent

“ That is, the absorbent must be able to absorb and hold large amounts of gas per unit weight of absorbent. Its life must be measured in days against ordinary concentrations of gas. It is further necessary that the gas be held firmly and not in any loose combination which might give up minute traces of gas when air is, for long periods of time, breathed in through a canister which has previously been exposed to gas. ”

“ When on the contrary some branches of the absorbent systems have their motions inverted in consequence of the previous exhaustion of their sensorial power by any violent stimulus, other branches of it have their absorbent power greatly increased. Hence continued vomiting, or violent cathartics, produce great absorption from the cellular membrane in cases of dropsy; and the fluids thus absorbed are poured into the stomach and intestines by the inverted motions of the lacteals and lymphatics. ”

“ When the cellular absorbents are become insensible to their usual irritations, it most frequently happens, but not always, that the cutaneous branch of absorbents, which is strictly associated with them, suffers the like inability. ”

“ The cold dampness of the hands of some people is caused by the deficient absorption of perspirable matter; the clammy or viscid feel of it is owing to the mucous part being left upon the skin. The coldness is produced both by the decreased action of the absorbent system, and by the evaporation of a greater quantity of the perspirable matter into the air, which ought to have been absorbed. ”

“ One of the first necessities in the development of absorbents and gas masks was a method of testing them and comparing their deficiencies. While the ultimate test of the value of an absorbent, canister or facepiece is, of course, the actual man test of the complete mask, the time consumed in these tests is so great that more rapid tests were devised for the control of these factors and the man test used as a check of the purely mechanical methods. ”

“ The second necessity is that the excrementitious matters should be rapidly absorbed, as they are being constantly poured out from the skin, so that the material must be absorbent in the highest degree, otherwise the fluids remain in contact with the skin to irritate it, and the atmospheric air confined between the undergarment and the skin rapidly becomes surcharged with gases and moisture, and so acts like a warm jacket around the skin. ”

“ Our absorbent system then seems to receive those contagious matters, which it has before experienced, in the same manner as it imbibes common moisture or other fluids; that is, without being thrown into so violent action as to produce sensation; the consequence of which is an increase of daily energy or activity, till inflammation and its consequences succeed. ”

“ These are: absorptive activity, absorptive capacity, versatility, mechanical strength, chemical stability, low breathing resistance, ease of manufacture and availability of raw materials.
Absorptive activity, or a very high rate of absorption, is one of the more important properties of a satisfactory absorbent. A normal man when exercising violently breathes about 60 liters of air per minute, and since inhalation occupies but slightly more than half of the breathing cycle, the actual rate at which gas passes through the canister during inhalation is about 100 liters per minute. ”

“ We eat our bread and milk and notice that bread is absorbent, and we overhaul our experience to discover other things which we know to be absorbent also, and we do what we can to compare these things as to whether they are less absorbent or more absorbent than bread. ”

“ Sulphuric ether, formic ether, and acetic ether, being placed in bulbous flasks, [4] their vapors were soon diffused in the air above the liquid. On placing these flasks, whose bottoms only were covered by the liquid, behind the rotating disk, so that the intermittent beam passed through the vapor, loud musical tones were in each case obtained. These are known to be the most highly absorbent vapors which my experiments revealed. Chloroform and bisulphide of carbon, on the other hand, are known to be the least absorbent, the latter standing near the head of diathermanous vapors. ”

“ Such experiments, recently verified, entirely dispose of the hypothesis that liquid films were the cause of the observed absorption.
The vapor-hesion hypothesis involves the assumption that liquids exert on radiant heat an absorbent power which is denied to their vapors. It assumes, in other words, that the seat of absorption is the molecule considered as a whole, and not the constituent atoms of the molecule. For, were the absorption intra-molecular, the passage from the liquid to the vaporous condition, which leaves the molecules intact, could not abolish the absorption. ”

“ The explanation has, however, been carried a step further, by experiments shewing that the absorption of odors by dead matter, such as clothing, is greatly affected by color, black being the most powerful absorbent, then blue, red, yellow, and lastly white. ”

“ This is to compress the bowels and increase their absorption, and it thus removes one principal cause of corpulency, which is the looseness of the skin. Secondly, he should omit one entire meal, as supper; by this long abstinence from food the absorbent system will act on the mucus and fat with greater energy. Thirdly, he should drink as little as he can with ease to his sensations; since, if the absorbents of the stomach and bowels supply the blood with much, or perhaps too much, aqueous fluid, the absorbents of the cellular membrane will act with less energy. ”

“ Those, which open their innumerable mouths into the cells of the whole cellular membrane; and whose use is to take up the fluid, which is poured into those cells, after it has done its office there; may be called cellular absorbents.
Those, which arise from the internal surfaces of the membranes, which line the larger cavities of the body, as the thorax, abdomen, scrotum, pericardium, take up the mucus poured into those cavities ”

“ When the sanguiferous system is full of blood, the absorbents cannot act so powerfully, as the progress of their contents is opposed by the previous fulness of the blood-vessels; whence stimulants in that case increase the action of the secerning system more than of the absorbent one ”

“ Contractility of texture is evident in the absorbent system. 1st. When the thoracic duct is distended even119 in a recent dead body, and the fluid is discharged by puncture, it immediately contracts. 2d. All the absorbents contract also as soon as there is no more fluid in their cavity. This phenomenon is remarkable during the absorption of chyle; when that is finished, these vessels evidently disappear by the effect of this contraction. 3d. The absorbent glands, swelled at the moment chyle is passing through them, afterwards lose much of their size by this contractile power. ”

“ When the defect of the due action of both the absorbent and secerning vessels of the liver affects women, and is attended with obstruction of the catamenia, it is called chlorosis; and is cured by the exhibition of steel, which restores by its specific stimulus the absorbent power of the liver ”

“ Can any one explain how these partial sweats should relieve the difficulty of breathing in anasarca, but by supposing that the pulmonary branch of absorbents drank up the fluid in the cavity of the thorax, or in the cells of the lungs, and threw it on the skin, by the retrograde motions of the cutaneous branch? for, if we could suppose, that the increased action of the cutaneous glands or capillaries poured upon the skin this fluid, previously absorbed from the lungs; why is not the whole surface of the body covered with sweat? why is not the skin warm? ”

“ From the fact in physics that liquids rise in capillary tubes, the inference has been drawn that absorption [165] in living vessels also takes place from capillary attraction. But in the animal body the application of the principle is undoubtedly modified by the properties peculiar to organization, and one of the most remarkable proofs of this is the circumstance of the absorbent vessels in different situations having to some extent a specific adaptation to the qualities of the substances upon which they are severally destined to act. ”

“ The ocean, itself a bad absorbent of heat.
Darwin.
2. (Med.) Any substance which absorbs and neutralizes acid fluid in the stomach and bowels, as magnesia, chalk, etc.; also a substance (e. g., iodine) which acts on the absorbent vessels so as to reduce enlarged and indurated parts.
3. pl. (Physiol.) The vessels by which the processes of absorption are carried on, as the lymphatics in animals, the extremities of the roots in plants. ”

“ In vertebrate animals this is done by the lymphatics and lacteals, in plants chiefly by the roots. See Absorbents.
In physics, absorption of colour is the phenomenon observed when certain colours are retained or prevented from passing through transparent bodies; thus pieces of coloured glass are almost opaque to some parts of the spectrum, while allowing other colours to pass through freely. In chemistry absorption is the taking up of a gas by a liquid, or by a porous solid. ”

“ We cannot deny that in the natural state the sensibility of the absorbents has a particular type, to which certain substances are alone accommodated, and which alone on this account can be absorbed. The exercise of the organic sensibility then always pre-exists in absorption, as it does in secretion, nutrition, &c. Thus in the physical phenomena, the exercise of gravity always precedes the fall of heavy bodies. ”

“ Davy found by experiment that when an animal is bled to death, the last portions of blood that flow are of a much lower specific gravity than that which flows first, in consequence of the former containing more water, which it may be inferred was derived by the increased activity of the absorbents, exerted chiefly on mucous and serous membranes. ”

“ And when the intestinal absorbents act too violently, as when too great quantities of fluid have been drank, the urinary absorbents invert their motions to carry off the superfluity, which is a new circumstance of association, and a temporary diabetes supervenes. ”

“ Effusions of water into large cavities, as into that of the abdomen or thorax, or into the ventricules of the brain or pericardium, are more difficult to be reabsorbed, than the effusion of fluids into the cellular membrane; because one part of this extensive sponge-like system of cells, which connects all the solid parts of the body, may have its power of absorption impaired, at the same time that some other part of it may still retain that power, or perhaps possess it in an increased degree ”

“ The best proof of the extreme variety of the capacity of the absorbents, is the necessity of choosing particular bodies in order to inject them, the very great difficulties that often take place in finding them in some subjects, whilst they are seen immediately in others, and can be traced in the inferior and superior extremities, through the cellular texture, without having glands for a guide. ”

“ Hence also it is that such people receive great benefit from the use of Absorbents, which uniting with the Acids neutralize them, and relieve nature when she has not strength enough herself to get the better of them. ”

“ The organs of exhalation and absorption, the serous membranes, the thoracic duct, the great right lymphatic vessel, and the secondary absorbents of all the parts have a distribution universally unequal and irregular. ”

“ We frequently observe an unusual quantity of mucus or other fluids in some diseases, although the action of the glands, by which those fluids are separated from the blood, is not unusually increased; but when the power of absorption alone is diminished. ”

“ The Decomposition of any remaining Portion, and the adoption of measures best calculated to obviate its absorption. Where the substance is in a solid form, and acts by absorption, we should be very cautious how we favour its solution; while, if it exists in a liquid state, our object must be to render its active portion insoluble; this problem involves a series of questions which are wholly chemical. In order to prevent, or retard, the absorption of the active matter, we must, to a great degree, depend upon the agency of vital adjuvants ”

“ All soluble mineral substances—acids, alkalies, salts, and soluble compounds of the earths and metals—are absorbed in the stomach and intestines. The conditions and the process of absorption have been already stated. When solid they are first dissolved, when in a dense solution diluted down by the gastric fluid before they are absorbed. Thin watery liquids are quickly taken up. Motion on one side, and pressure on the other, hasten the process. I am not inclined to make any exception to this rule. This leads me to make some remarks on the Endosmotic theory of the action of saline purgatives. ”

“ Suppose the class to suggest as definitions that substances in the solid state are “hard,” in the liquid state “wet,” and in the gaseous state “invisible,” they will be much interested in having the imperfection of these definitions brought home to them by the help of the liquid metal mercury, which does not “wet” glass or porcelain, and of the visible gas chlorine, and in being led to find out the true distinctions [295] by observing the different behaviour of solids, liquids, and gases respectively when placed in vessels of differing shapes and sizes. ”

“ But where the bulk is considerable, or where the activity is such as to involve much waste and repair, or where both these characteristics exist, there is a necessity for a system of blood-vessels. It is not enough that there be adequately extensive surfaces for absorption and aeration; for in the absence of any means of conveyance, the absorbed elements can be of little or no use to the organism at large. ”