Dilution

“ This fact alone shows that potentization leads into a realm of material effects at variance with the ordinary scientific conception of matter. Moreover, we can carry the dilutions as far as we please without destroying the capacity of the substance to produce physiological reactions. On the contrary, as soon as its original capacity is reduced to a minimum by dilution, further dilution gives it the power to cause actually stronger reactions, of a different and usually opposite kind. ”

“ One part of hydrogen is sufficient to saturate and fix above five of carbon, and they require nearly sixteen parts of oxygen to complete their formation into alcohol, while the water of dilution undergoes a proportionate decomposition and recomposition, to assist the resolutions and combinations, and support the admirable equilibrium preserved by nature. ”

“ Kwik Set, Inc., v. Welch Grape Juice Co., 2 Cir., 86 F.2d 945, 947. No such discovery was made here. The advantages said to accompany a dilute solution do not correspond to any particular dilution point or range. ”

“ It is plain that the standard solutions must be scrupulously protected from concentration or dilution, after their value has been established. Accordingly, great care must be taken to thoroughly rinse out all burettes, flasks, etc., with the solutions which they are to contain, in order to remove all traces of water or other liquid which could act as a diluent. It is best to wash out a burette at least three times with small portions of a solution, allowing each to run out through the tip before assuming that the burette is in a condition to be filled and used. ”

“ III contains 0.00001 c.c. of the original sewage.
1 c.c. of dilution No. IV contains 0.0000001 c.c. of the original sewage.
7. Pour a set of gelatine plates from the contents of each capsule, three plates in a set, and containing respectively 0.2, 0.3, and 0.5 c.c. of the dilution. Label carefully; incubate at 20° C. for three, four, or five days.
8. Enumerate the organisms present in those sets of plates which have not liquefied, probably those from dilution III or IV, and calculate therefrom the number present per cubic centimetre of the original sample of sewage. ”

“ In the eighth dilution, to obtain a drop of the tincture the whole Atlantic Ocean full of alcohol would be necessary. Dr. Black, to whom I have referred, says he uses the first, third, sixth, ninth, up to the thirtieth dilution. Imagine the effect of one-drop doses of the thirtieth dilution! ”

“ According to this theory, each dilution and dynamization breaks down or lays open a new set of molecules, and allows their smaller corpuscles to escape from their confinement and become active; and reasoning abstractly upon the endless divisibility of matter, they arrive at the conclusion that the power of medicinal substances may be endlessly developed by these means. ”

“ Quantity of Diluting Water Needed.—In a large majority of the problems of disposal of sewage by dilution it is not necessary to add sufficient diluting water to oxidize completely all organic matter present. Ordinarily it is sufficient to prevent putrefactive conditions until the flow of the stream, lake, or tidal current, has reached some large body of diluting water or where putrefaction is no longer a nuisance. It is never desirable to allow the oxygen content of a stream to be exhausted as putrescible conditions will exist locally before exhaustion is complete. ”

“ Disposal by dilution in large streams of water is regarded as satisfactory in many places—where the water of the stream is not to be used397 for drinking or cooking—provided the flow of the stream is always copious enough to dilute and disperse the sewage so widely as to prevent putrefaction and substitute oxidation. For purification by bacterial action no single method is found adapted to all conditions. ”

“ It will also occur to the reader that, since a small bulk of formaline represents a large volume of the diluted preservative, it is very conveniently stored, and a very small bottle of it taken for outdoor work may, on dilution with water, be made to yield all that is required for the preservation of the takings of a successful day, or even of a longer period. ”

“ If peak area is above the linear range of the working standards, dilute an aliquot of the desorbed liquid with pentane, reanalyze and apply the appropriate dilution factor in calculations. Measure peak area. ”

“ It is also more to be depended on for weak solutions than strong ones. By carefully diluting a strong acid with an equal weight, or twice or thrice its weight of water, and allowing the mixture to again acquire its normal temperature, the sp. gr. may be taken as a guide in all cases in which great accuracy is not required. When such dilution is made it only becomes necessary to multiply the indication furnished in the Tables by 2, 3, or 4, as the case may be. ”

“ At very great dilutions the dissociation is complete, and equivalent solutions of the most various acids then contain the same number of hydrogen-ions, or, in other words, are equally strong; and the same is true of the hydroxyl-ions of bases. The dissociation also decreases with increasing concentration, but at different rates for different substances, and the relative “strengths” of acids and bases must hence change with concentration, as was indeed found experimentally. ”

“ For quite dilute solutions, in which the friction may be assumed to be approximately constant, the conductivity will depend, not only on the mobilities of the ions, which may be taken to be the same as for solutions of extreme dilution, but also on the proportion of electrolyte that is ionized, i.e. ”

“ Tobacco, coffee, alcohol, hashish, prussic acid, strychnine, are weak dilutions: the surest poison is time. ”

“ How is it to get into the plant?
When one liquid, say spirit, is poured into another, say water, the two gradually mix. If we suppose these liquids to consist of a number of molecules, then, mixture may be taken to be the result of the displacement say of one molecule of water by one molecule of spirit, and so, throughout the whole quantity of liquid, there is displacement and replacement till at length equilibrium is restored and a thorough diffusion results. This power of diffusion does not always exist. The molecules of water and of oil will not mix or diffuse freely through each other. ”

“ The peculiar manner in which hydrogen gas appears to dissolve solid substances,—as iron, potassium, sodium, sulphur, phosphorus, selenium, and arsenic, may be explained by regarding the results as a manifestation of the powers of chemical affinity over the forms of bodies. In like manner, the solution of salt in water, or the mixture of alcohol in that fluid, may be viewed as chemical phenomena, although usually considered as simple cases of solution or mixture: alterations of temperature and other physical changes taking place in either. ”

“ Remove any portion and a part of the space will be left unoccupied by liquid. Part of the liquid surface is then otherwise conditioned than by the form of the wall or bounding surface of the region; and if the portion of the wall not in contact with the liquid is removed the form and quantity of the liquid are in no way affected. Hence a liquid can be kept in an open vessel; a gas cannot so be. To quote the differentia of Sir Oliver Lodge: “A solid has volume and shape; a liquid has volume, but no shape; a gas has neither volume nor shape.” ”

“ In such a case the molecules of the solutum will be divided between the liquid and the gas in a (sensibly) constant ratio (the volume of the liquid and gas being kept constant) , simply because every molecule, moving as if there were no others, would spend the same part of its time in the vapor and in the liquid as if the others were absent, and the number of the molecules being large, this would make the division sensibly constant. ”

“ That the natural fluid can hold in solution only such a proportion of metallic ingredients as the acids and gases contained therein, are capable of dissolving; while the factitious mineral waters are not only cheaper and more efficacious, but retain their virtues without diminution, are impregnated with a larger volume of gas, and may be composed of any quantity and quality of salt or earth, according to particular circumstances. ”

“ They are facts, however; liquids capable of being mixed, if connected by porous arches (bibulous paper is convenient for illustrating by experiment) reverse the rule men have accepted to explain the phenomena of liquid equilibrium, for I repeat, the lighter one rushes into that which is heavier, and the surface of the heavier liquid rises. You can try the experiment with alcohol and water, taking precautions to prevent evaporation, or you can vary the experiment with solutions of various salts of different densities ”

“ However clear and pellucid the liquid may have been, when first prepared, however carefully it may have been freed from even the finest visible impurities, by straining and filtration, it will not remain clear. After a time it will become cloudy and turbid; little bubbles will be seen rising to the surface, and their abundance will increase until the liquid hisses as if it were simmering on the fire. By degrees, some of the solid particles which produce the turbidity of the liquid collect at its surface into a scum, which is blown up by the emerging air-bubbles into a thick, foamy froth. ”

“ Bodies soluble in water may be weighed in some other fluid, as alcohol, ether, olive oil, &c., and their proportional weight to that of this fluid being thus ascertained, their density compared with that of water is readily calculated or they may be enveloped in wax or other suitable substance to protect them, and then treated by the method just given for substances lighter than water. ”

“ The dehydrating agents rapidly lose their efficiency on exposure to the air.
CRUCIBLES It is often necessary in quantitative analysis to employ fluxes to bring into solution substances which are not dissolved by acids. The fluxes in most common use are sodium carbonate and sodium or potassium acid sulphate. In gravimetric analysis it is usually necessary to ignite the separated substance after filtration and washing, in order to remove moisture, or to convert it through physical or chemical changes into some definite and stable form for weighing. ”

“ When a difficultly soluble substance is formed in a solution beyond the point of saturation of the solution, the substance in question separates from the solution in a new phase, according to the principles just laid down. Ordinarily, if the substance is a solid, a precipitate is formed; if a gas, a gas escapes; if a liquid, a liquid separates out, which is immiscible with the solution in which it is formed. ”

“ When two fluids are diffused together without undergoing any change of their chemical properties, they are said simply to be mixed, and not combined; as milk and water when poured together, or as oxygen and azote in the common atmosphere. So when salt or sugar is diffused in water, it is termed solution, and not combination; as no change of their chemical properties succeeds. ”

“ 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. ”

“ VII. In case the water be suspected to contain any salts, it will be advisable gently to boil a quantity of the dry substance obtained by distillation, in five or six times its weight of pure common distilled water, such as is totally divested of all mineral particles. By this process, the saline matter will be dissolved or suspended in such water, in the form of a solution, which, on being filtred, and evaporated to dryness, will re-produce its salt. ”

“ When a solid material having a proper degree of porosity or aggregation is selected, the stream of gas passing through it is broken up most thoroughly, and by employing several separate layers of such material, every portion of the gas is exposed equally to the action of the chemical reagent by the time the gas emerges from the vessel. The amount of pressure so consumed is less than that in a liquid purifier where much fluid is present ”

“ B. Which sentences state causes and which state effects in the following paragraphs?
1. The power of water to dissolve most minerals increases with its temperature and the amount of gases it contains. Percolating water at great depths, therefore, generally dissolves more mineral matter than it can hold in solution when it reaches the surface, where it cools, and, being relieved of pressure, much of its carbonic acid gas escapes to the atmosphere or is absorbed by aquatic plants or mosses. ”

“ When solutions of these substances are placed in sufficiently close contact with many animal products, albumen, milk, muscular fibre, and animal membranes, the acid or salt leaves the water in which it was dissolved, and enters into combination with the animal substance: which substance, after being thus acted upon, is found to have lost its tendency to spontaneous decomposition, or putrefaction. ”

“ The resultant tendency is for the solutions on the two sides of the membranes to become equal in concentration by movement of the liquid from the less dense to the more dense portion, instead of by movement of the dissolved materials toward the less dense part of the solution as in the case of diffusion when solutions of different concentrations are brought in contact with no membrane to interfere with free diffusion. ”