Saline solution

“ Such an arrangement, if erected upon a scale sufficiently extensive, with the medium of a neutro-saline solution, would, in his opinion, produce large quantities of acids and alkalies with very little trouble or expense.
249 Alterations in chemical equilibrium are constantly taking place in Nature, and he thinks it probable that the electric influence, in its faculties of decomposition and transference, may considerably interfere with the chemical changes occurring in different parts of our system. ”

“ 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. ”

“ Ox-gall and pig-gall are laxatives only; they have no effect on the liver, but can be added to other purgatives in pill forms.
Salines largely diluted may be given to strong adults: Epsom or Rochelle salts quite early in the morning, a solution of sulphate of magnesia with dilute sulphuric acid, to which dried sulphate of iron may be added, are quite popular; and of the bitter waters, Hunyadi Jânos, Friedrichshall, or Pullna water serves the purpose. One grain of sulphate of quinia added to a saline will increase its effect. The milder laxative waters are to be preferred to the bitter waters. ”

“ The above potash lye usually gets a reddish tint in the course of the process in consequence of a little manganesic acid coming over with the chlorine, but it gradually loses this colour as the saturation becomes complete, when the solution turns yellow. The tubes for conveying the gas should be of large diameter, if they be plunged into the saline solution, because the crystallization which takes place in it is apt to choke them up. ”

“ The above solutions are suitable for chemical baths. With the exception of the first, they furnish in their boiling-points temperatures, as nearly as can be obtained, 10° above each other. They were chosen by Mr Williams because, in ‘fractionating’ volatile substances, it is usual to separate the distilled products by differences of temperature equal to 10° Fahr. In long operations it is found inconvenient to employ a saturated saline solution for a bath (by which the highest temperature would be obtained) , as the constant evaporation of the water induces the crystallisation of605 the salt. ”

“ A grain of salt no larger than a pin-head dropped into a pint of distilled water, will give a distinct chlorine test when nitrate of silver solution is added. Stronger, or even weaker, salt solution can be used by the experimenter while he is working into practice. ”

“ It depends upon the fact that salol is not absorbed until it reaches the intestine and is decomposed by the alkaline intestinal juices.
The patient is given 15 grains of salol with a test-breakfast, and the urine, passed at intervals thereafter, is tested for salicyluric acid. A few drops of 10 per cent. ferric chlorid solution are added to a small quantity of the urine. A violet color denotes the presence of salicyluric acid. It appears normally in sixty to seventy-five minutes after ingestion of the salol. A longer time indicates impaired motor power. ”

“ The hydrosol of silica prepared by mixing an excess of hydrochloric acid with a solution of sodium silicate, may be freed from the admixtures both of hydrochloric acid and salt, sodium chloride, by means of dialysis, [17] as Graham showed (in 1861) in enquiring into the nature of colloids (Chapter I.) , and making many other important chemical investigations. The solution, containing the acid, salt, and silica, all dissolved in water, is poured into a dialyser—that is, a vessel with a porous diaphragm surrounded by water. Certain substances pass more easily through the diaphragm than others. ”

“ When pure, this salt is colourless and odourless; it forms cubic or octahedral crystals, which are anhydrous; it is freely soluble in water and in boiling alcohol, but most of it separates from the latter as the solution cools; it is fusible; and undergoes no change, even at a full red heat, in close vessels; it exhibits an alkaline reaction; when exposed to the atmosphere, it absorbs moisture, and acquires the smell of hydrocyanic acid. If it effervesces with acids, it contains carbonate of potassium, and if it be yellow it contains iron. ”

“ Common salt is a combination of the metal sodium and the gas chlorine. There are many places, of which Cheshire is a notable example, where vast quantities of this salt lie buried in the earth.
Fortunately it is very easily dissolved in water so that if wells be sunk in a salt district the water pumped from them will have much salt in solution in it. This is how the underground deposits are tapped. It is not necessary for men to go down as they do after coal, for the water excavates the salt and brings it to the surface. ”

“ This is the dialyzing vessel, and it is into this that the mixture of silicate and hydrochloric acid must be put. The solution should not be more than an inch deep in the dialyzing vessel, which is then made to float upon distilled water in a larger vessel of suitable size. The distilled water should be changed every day, until no precipitate can be obtained in it with nitrate of silver, and when this point is arrived at, all the chloride of sodium will have passed through the vegetable parchment into the larger vessel of water, and nothing but silicic hydrate will remain behind in solution. ”

“ A very serious difficulty presents itself in the great thickness of many strata of salt; which, if regarded as the solid residuum of sea-water, must have necessarily required a proportionate volume of water, unless the seas of those distant periods contained a larger amount of saline ingredients than they do at the present time: an inference for which there are no reasonable grounds.
Wherever there are deposits of the chloride of sodium, they are almost always accompanied with layers and intercalations of gypsum ”

“ Salt-petre is separated from the brine which first affords it, or from the water with which it is washed out of nitrous earths, by the process commonly used in crystallizing salts. In this process the brine is gradually diminished, and at length reduced to a small quantity of an unctuous bitter saline liquor, affording no more salt-petre by evaporation; but, if urged with a brisk fire, drying up into a confused mass which attracts water strongly, and becomes fluid again when exposed to the open air. ”

“ All substances which are soluble in water have the faculty of penetrating through a membrane swollen in water, but the velocity of penetration is not equal, and in this respect the dialyser separates substances like a sieve. The silica passes less rapidly through the diaphragm than the sodium chloride and hydrochloric acid, so that by repeatedly changing the external water it is easy to effect the extraction of the chlorine compounds from the dialyser, which will finally only contain a solution of silica. ”

“ A number of different methods of sterilisation have been tried, but so far as the existing knowledge of the subject extends, the application of chlorine in one form or another is generally admitted to be the most efficient and economical process. The chlorine may be applied in the form of a solution of chloride of lime, or as a hypochlorite of sodium, or of magnesium. ”

“ By this operation common salt is got from seawater and salt springs, both artificially, and, in hot countries, by the natural heat of the sun. When the water is no more than is just sufficient to dissolve the salt, it is called a saturated solution, and on evaporating the water further, the salt begins to separate, forming little regular masses called crystals. Sugar may be made in like manner to form crystals, and then it is sugar-candy. ”

“ Common salt constitutes the mineral halite, the composition of which is sodium chloride. It is rarely found perfectly pure in nature, but is commonly mixed with other saline materials, such as gypsum and anhydrite, and occasionally with salts of potassium and magnesium. The general grade of rock-salt deposits, where not admixed with clay, is perhaps 96 to 99 per cent of sodium chloride. ”

“ A cooling and stimulating lotion for sprains and bruises may be made by dissolving two ounces of common salt, nitrate of potash and chloride of ammonia in a quart of water.
Use pure cooking salt in normal salt solution, which contains six of one per cent (about fifty grains to a pint) , or may be made at once by adding a heaping teaspoonful of pure salt into a quart of sterilized water at a temperature of 100° to 110° F. In cases of azoturia give plenty of salt; it acts as a diuretic, makes the horse thirsty and causes him to drink water freely and flushes the kidneys. ”

“ The residue is then poured on to a piece of small wire gauze, washed thoroughly, and squeezed out. The moist mass of fibre is loosened and teased out, placed in a beaker, and submitted to the action of chlorine gas for an hour. The bright yellow mass is then washed with water and immersed in a solution of sodium sulphite (twenty grammes of sodium sulphite in 1,000 cc. of water) . ”

“ This test is done by dropping in some nitrate of silver solution, which produces a white precipitate, caused by the silver combining with the chlorine, which is the principal element in common salt. This is an excessively fine test, and the nitrate of silver will detect an incredibly small trace of common salt in water. The worst effect that common salt has in water, is to cause priming. Where it is present to any great extent, the blow-off cock should be used frequently on the road; and a surface-cock is quite an aid in keeping the boiler in order. ”

“ It requires more than 1200 parts of water for its solution: for its perfect purification, it should be heated with a solution of chloride of potassium, the insoluble portion separated whilst the liquid is lost, and the peculiar salt allowed to deposit as the temperature falls. When heated, it behaves like the salt of silver. ”

“ The toxic and antitoxic actions of neutral salts form a case in point. Pure solutions of sodium salts, even sodium chloride, are strongly toxic to many cells, particularly those of marine organisms, as the work of J. Loeb and his successors has shown with especial clearness; but if to the pure solution a little calcium salt is added, this toxic action is prevented or greatly diminished; the calcium (or other favorable salt) counteracts the toxic action of the sodium salt—in other words, has an antitoxic action. ”

“ If the purifying material is not hygroscopic, water, calcium chloride solution, or dilute glycerin may be used for sealing purposes; but if the material, or any part of it, does absorb water, the liquid in the seal should be some non-aqueous fluid like lubricating oil. Clamped lids are more suitable for small purifiers, sealed lids for large vessels. Care must be taken that condensation products cannot collect in the purifying vessel. If a separate drying material is employed in the same purifier the space it takes must be considered separately from that needed by the active chemical reagent. ”

“ In the common condition of the body it is not possible for the secretion of the skin to be very largely increased, or rendered fluid. Suppose, then, a soluble saline, as the Sulphate of Soda or Magnesia, or Tartarized Soda, to have obtained entry into the blood, it has the choice of being excreted by the kidneys or the bowels. The alternative appears to depend mainly upon the amount of the dose. A small quantity may pass in the urine, and will not produce purging. But a large quantity cannot so pass; it is excreted by the glands of the bowels, and acts as a Purgative. ”

“ Dissolve the suspected stain in a few drops of normal salt solution upon a slide. If a liquid is to be tested, evaporate some of it upon a slide and dissolve the residue in a few drops of the salt solution. Let dry, apply a cover-glass, and run glacial acetic acid underneath it. Heat very gently until bubbles begin to form, replacing the acid as it evaporates. Allow to cool slowly. When cool, replace the acid with water, and examine for hemin crystals with two-thirds and one-sixth objectives. ”

“ It was obtained as a by-product in many chemical reactions, and subsequently used to be extracted from kainite, one of the Stassfurt minerals, but the process is now given up because the salt can be produced cheaply enough from the chloride by decomposing it with sulphuric acid and calcining the residue. To purify the crude product it is dissolved in hot water and the solution filtered and allowed to cool, when the bulk of the dissolved salt crystallizes out with characteristic promptitude. ”

“ Salicylic acid is now never given internally, being replaced by its sodium salt, which is much cheaper, more soluble and less irritating to mucous membranes. The salt has a sweet, mawkish taste.
Salicylic acid and salicin (q.v.) share the properties common to the group of aromatic acids, which, as a group, are antiseptic without eing toxic to man-a property practically unique; are unstable in the body; are antipyfetic and analgesic; and diminish the excretion of urea by the kidneys. ”