Solvent

“ In all cases it should be remembered that we are dealing with equilibria between two components (we confine our attention in the first instance to such) , the solution being constituted of these components in variable and varying amounts. The change from the case where the one component is in great excess (ordinarily called the solvent) to that in which the other component predominates, may be quite gradual, so that it is difficult or impossible to say at what point the one component ceases to be the solvent and becomes the solute. ”

“ The solvent power which holds all these solid substances in solution, and which contributes to their agreeable taste, is the carbonic acid gas with which the water is so freely charged. This free carbonic acid gas is probably formed by the decomposition of the carbonates which compose the rock. The water, impregnated with it, becomes a powerful solvent, and, passing through different strata, absorbs the various mineral substances which compose its solid constituents. ”

“ Broadly speaking, water is the most general solvent, and alcohol is perhaps second in solvent power.
3. Temperature. The weight of a solid which a given liquid can dissolve varies with the temperature. Usually it increases rapidly as the temperature rises, so that the boiling liquid dissolves several times the weight which the cold liquid will dissolve. In some instances, as in the case of common salt dissolved in water, the temperature has little influence upon the solubility, and a few solids are more soluble in cold water than in hot. ”

“ If a fluid so simple as water, braided of only three molecules of Matter, two of hydrogen and one of oxygen, can be so powerful a solvent, it follows that a fluid so complex as the Ether, woven and interwoven of molecules of all the elements, that is, of molecules of every form of Matter, must be dynamic in the highest degree, must be an omnipotent solvent: if water, consisting of only two elements, can hold in solution, besides its own constituents, ten or a dozen other elements, the Ether, consisting of all the elements, a fortiori can hold in solution all these elements. ”

“ As a rule a simple explanation can be found for every apparently abnormal result, and in the accidental retention of a portion of the solvent used in the manufacture, will frequently be found an explanation of the trouble experienced. ”

“ The discovery of the chemical solvent, which forms the subject of the patent above described, has excited considerable interest in the philosophic world, not only from its probable usefulness as a new article of commerce, but also from two very extraordinary characteristics which it is found to possess, viz., that, in a liquid state, it has less specific gravity than any other liquid known to chemists, being considerably lighter than sulphuric ether, and, in a state of vapour, is heavier than the most ponderous of the gases. ”

“ But in whichever of these ways solidity shall be procured, it must be brought about by first inducing fluidity, either immediately by the action of heat, or mediately with the assistance of a solvent, that is, by the operation of solution. ”

“ Extraction, in chemical technology, is a process for separating one substance from another by taking advantage of the varying solubility of the components in some chosen solvent. The term “lixiviation” is used when water is the solvent. In laboratory practice all the common solvents are employed. With small quantities it may suffice to shake the substance with the solvent, the mixture being heated if necessary, filter and distil or otherwise remove the solvent from the distillate. ”

“ Chemical Composition. When pure it consists of oxygen, hydrogen, and carbon; the rectified æther however still contains some water and alcohol, for Lovitz obtained an æther of 632. Solubility. One part requires for its solution ten of water; with alcohol and ammonia it unites in every proportion. Solvent Powers. It is one of 268the most powerful solvents known in vegetable chemistry, as it dissolves balsams, resins, gum-resins, wax, camphor, extractive, &c.; it takes up about a twentieth of its weight of sulphur, but it exerts no solvent power upon the fixed alkalies. Forms of Exhibition. ”

“ If the dissociation of salts is a reality and is complete in a dilute solution, any of the properties of a saline solution whatever should be represented numerically as the sum of three values, of which one concerns the positive ion, a second the negative ion, and the third the solvent. ”

“ But you comprehend the result—man's complete triumph over disease by this process of dissolution aad rehabilitation. The foundation was my ancestor’s discovery that every substance—iron, gold, or any metal, flesh, bone, gristle, etc.,—may be dissolved by some chemical or combination of chemicals, and his inference was that a universal solvent might by their combination, be discovered. ”

“ Water will dissolve many substances, but in varying degrees, i.e., of some it will dissolve much, of others, little, and some not at all. Further, different liquids have different solvent powers. Alcohol will dissolve resin and shellac, but it will not dissolve gum arabic, which is soluble in water. Benzine dissolves grease. ”

“ Water is the best solvent known. The alchemists of old spent much time and energy trying to find the universal solvent, believing that thereafter it would be easy to discover a method of making base metals noble. ”

“ Hence, if it be desired to increase the rate of solution, recourse must be had to stirring, shaking, or some such mechanical motion. But if once a uniform solution is formed, it will remain uniform, no matter how heavy the dissolved substance is, or how long the solution be left at rest, which fact again shows the presence of a force holding together the particles of the body dissolved and of the solvent. ”

“ If each mole- cule of the solute combines with a certain number of molecules of the solvent in such a way as to render them inactive for evapora- tion, we get a lowering of vapour pressure. Let us assume that the ratio pjp' of the vapour pressures of the solvent and solution is equal to the ratio of the number of free molecules of solvent to the whole number of molecules in the solution. Each molecular complex, formed by solution and solvent, is treated as a single molecule. ”

“ Therefore this incomparable subject is called an universal solvent, because by its benefit, many incredible things are performed in the preparation of good Medicines, and also in the preparation of metals, yet let no man believe that it dissolveth metals swiftly and violently, like aqua fortis, aqua regia, or other corrosive waters, not in the least, but worketh altogether after another manner, viz. Vegetables and Animals are dissolved in digestion, by the moist way, in which solution, the pure parts are separated from the impure. ”

“ The mordants that are to be united with stuffs are, as we have seen, insoluble of themselves, for which reason their particles must be divided by solution in an appropriate vehicle. Now this solvent or menstruum will exert in its own favour an affinity for the mordant, which will prove to that extent an obstacle to its attraction for the stuff. Hence we must select such solvents as have a weaker affinity for the mordants than the mordants have for the stuffs. ”

“ Another relation at which he worked was that the diminution in the vapour-pressure of a solvent, caused by dissolving a substance in it, is proportional to the molecular weight of the substance dissolved—at least when the solution is dilute. ”

“ But this may be nothing but allegory. By man is probably meant gold, and by lepers the other metals; and the medicine is the universal solvent or agent which transmutes. Alchemistic literature is full of allegories of this character. ”

“ Yet indestructible matter can as in the case of sugar, or any other chemical element, be recalled to life and even to its previous form. The molecule that cannot be divided by any physical means is divided by the universal solvent and resolved into something else. ”

“ Their idea of the way in which it would aid them to attain these ends does not seem to be very clearly stated in any work that I have consulted; probably they thought that a universal solvent would wash away all impurities from common materials and leave in absolute purity the higher substance, which constituted the gold of the adepts. But whatever their particular object may have been, it is well known that much time and labor were expended in the fruitless search. ”

“ This explains why salts are usually inactive and neutral in character, while acids and bases are active agents. Thus we see why the most positive or the most negative elements in general have the strongest affinities, while those intermediate in the list are inactive, and have weak affinities; why alloys of the metals are weak compounds; why a neutral substance, like water, has such a weak affinity for the salts which it holds in solution; and why an aqueous solution is regarded as a mechanical mixture rather than a chemical compound. ”

“ Certain solids also consist of two or more components which are united so as to show' similar effects. All these cases of solution are to be distinguished from chemical compounds on the one hand, and from simple mixtures on the other. When a substance contains its components in definite proportions which can only change, if at all, by sudden steps, it may be classed as a chemical compound. When the relative quantities of the components can vary continuously within certain limits, the substance is either a solution or a mixture. ”

“ 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. ”

“ But when you shake or stir salt or sugar in water, the particles divide up into smaller and smaller pieces, until probably each piece is just a single molecule of the salt or sugar. And these molecules get into the spaces between the water molecules and bounce around among them. They therefore act like the water and let the light through. This is a solution. The salt or sugar is dissolved in the water. Any liquid mixture which remains clear is a solution, no matter what the color. Most red ink, most blueing, clear coffee, tea, and ocean water are solutions. ”

“ Organic compounds, on which our life and living depend, consist chiefly of four elements: carbon, hydrogen, oxygen and nitrogen. These compounds are sometimes hard to analyze, but when once the chemist has ascertained their constitution he can usually make them out of their elements—if he wants to. He will not want to do it as a business unless it pays and it will not pay unless the manufacturing process is cheaper than the natural process. ”

“ It was formerly supposed that the substances found in plants and animals, mostly complex compounds of carbon, hydrogen and oxygen, could only be produced by "vital forces." If this were true it meant that chemistry was limited to the mineral kingdom and to the extraction of such carbon compounds as happened to exist ready formed in the vegetable and animal kingdoms. But fortunately this barrier to human achievement proved purely illusory. The organic field, once man had broken into it, proved easier to work in than the inorganic. ”

“ The conditions which regulate the solubility of bodies, and the power of solution, regarded either as a mechanical or a chemical process, are very obscure. We might be led to suppose, that those bodies possessing the largest amount of unoccupied space were capable of holding the greatest quantity of soluble matter dissolved. ”

“ 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. ”

“ From this it is evident that the analogy of substances forming a solution plays an important part, and as aqueous and all other solutions are liquids, there is good reason to believe that in the process of solution solid and gaseous substances change in a physical sense, passing into a liquid state. These considerations elucidate many points of solution—as, for instance, the variation of the co-efficient of solubility with the temperature and the evolution or absorption of heat in the formation of solutions. ”

“ Through solution, all soluble elements, which would otherwise remain locked in the inactivity of the solid state, are enabled to enter upon a new phase of mobility, of chemical life, as we may say. Only in water could colloid carbon compounds first be built up, and only from such substances could life originate. ”

“ C. Every liquid which, when placed in a white porcelain vessel to the depth of one inch, exhibits under daylight distinct color.
D. Every liquid which contains in solution, in every 100,000 [8] parts by weight, more than two parts of any metal, except calcium, magnesium, potassium and sodium.
E. Every liquid which in every 100,000 parts by weight contains in solution, suspension, chemical combination or otherwise, more than 0.5 metallic arsenic.
F. Every liquid which, after the addition of sulphuric acid, contains in every 100,000 parts by weight more than one part of free chlorine. ”