Green vitriol

“ The second group consists of the artificial reds obtained by burning or calcining raw materials, whose ferric hydroxide is more or less transformed by heat into ferric oxide, such as vitriol ochre, pit ochre and alum sludge.
Of late years the artificial earth colours have attained a high degree of importance. They are obtained in large quantities in the manufacture of sulphuric acid from green vitriol. ”

“ In a concentrated form sulphuric acid is commercially known as oil of vitriol, because for a long time it was obtained from green vitriol and because it has an oily appearance and flows from one vessel into another in a thick and somewhat sluggish stream, like the majority of oily substances, and in this clearly differs from such liquids as water, spirit, ether, and the like, which exhibit a far greater mobility. ”

“ Nine kilogrammes of green vitriol are dissolved in 100 litres of water, 15 kilogrammes of strong sulphuric acid are added, and then a solution of 15 kilogrammes of yellow prussiate in 100 litres of water. The solutions are kept in constant motion during the mixing. As soon as the decomposition is finished, without waiting for the precipitate to settle, steam is led in and 20 kilogrammes of nitric acid of 1·3298 specific gravity added in small portions. ”

“ Vit′rify, to make into glass.—v.i. to become glass.—ns. Vitrī′na, a genus of land molluscs forming a connecting-link between the slugs and true snails—the glass-snail; Vit′rine, a show-case made of glass and used to protect delicate articles. [L. vitrum, glass—vidēre, to see.]
Vitriol, vit′ri-ol, n. the popular name of sulphuric acid: a soluble sulphate of a metal—green vitriol=sulphate of iron, blue vitriol=sulphate of copper, white vitriol=sulphate of zinc.—v.t. Vit′riolāte, to convert into vitriol.—n. Vitriolā′tion, the act or process of converting into vitriol.—adjs. ”

“ Of these crystals he says: “A more beautiful appearance can hardly be imagined, and I am afraid I shall never see the like again.” He also noticed the formation of the dark brown compound which nitric oxide forms with a solution of green vitriol, and adds:—
“To determine whether the phenomena attending the impregnation of the solution of green vitriol with nitrous air depended in any measure upon the seeming astringency of that solution ... ”

“ These ochres are obtained as by-products in the manufacture of green vitriol from pyrites, and in alum manufacture; and, according to their origin, they are classed as vitriol ochre, so-called alum sludge, and pit ochre. All the basic ferric sulphates of which they are composed form fairly large crystals, and, therefore, in most cases, the covering power is small. On this account the products are of low grade and are put on the market at low prices, for which reason they are largely used in making cheap paints. ”

“ Meanwhile, the wound was kept clean and cool.
(1) Green vitriol, ferrous sulphate heptahydrate, a compound of iron, sulphur, and oxygen, crystallised with seven molecules of water, represented by the formula FeSO4 [.] 7H2O. On exposure to the air it loses water, and is gradually converted into basic ferric sulphate. For long, green vitriol was confused with blue vitriol, which generally occurs as an impurity in crude green vitriol. Blue vitriol is copper sulphate pentahydrate, CuSO4 [.] ”

“ White vitriol is chiefly manufactured in Germany.
It is used in medicine; and is employed in great quantities by varnishers, to make their oil varnishes dry more readily than they otherwise would. A fine white colour, called zinc-white, which is more durable 142than white lead, is prepared from it. Dyers use a considerable quantity of white vitriol to render deeper the colours produced by madder, cochineal, and other substances.
A pleasing experiment is made by mixing in a phial a small quantity of solution of white vitriol with a little liquid ammonia. ”

“ Thus chlorine and light destroy its colour, sulphuric acid changes it to indigo, which gradually becomes lilac, and nitric acid gives it a green hue. Solubility. It yields its colour and active ingredients to water, alcohol, proof spirit, wine, vinegar, and in a less degree to æther; the watery infusion, and the vinous tincture soon grow sour, and lose their properties, and the solution in vinegar becomes quickly colourless. Med. Uses. It is now never employed but for the sake of its colour or aromatic flavour, as an adjunct to other substances. ”

“ In order to determine whether it is sulphuric acid, the fluid must also be tested with nitrate of baryta followed by nitric acid: a heavy white precipitate is thus produced, which the excess of nitric acid does not redissolve.
4. Artificial Verdigris. Artificial verdigris is a common pigment, which is met with in the form either of earth-like masses, or of a light powder of a greenish-blue colour and peculiar disagreeable smell, approaching that of vinegar. Like blue vitriol it has a strong metallic, astringent taste. The effect of heat is peculiar. ”

“ A herd of turkeys, if given access to the tobacco-field, are a very valuable help. A negro from South Carolina told me a few days ago, that a solution of blue vitriol in water, sprinkled over the plants, will kill the worms. The remedy may be worth trying. Of course the solution must be made weak enough, so that it will not destroy the plants as well as the worms. ”

“ Subsequent experiments, however, showed that the light oil distils at a lower temperature than the heavy, and that if the heaviest specimens were distilled with water, the first portions that passed over produced precisely the same reaction as the light specimens above referred to, while the last portions that passed over, and especially the oil obtained from the water by distilling it, after saturating it with common salt, produced with oil of vitriol a splendid crimson color, the purity and intensity of which could hardly be surpassed. ”

“ By the action of the atmosphere on the arsenic it contains, arseniuretted hydrogen is formed—an extremely poisonous gas, very small quantities of which are sufficient to cause serious illness in the case of susceptible people. In spite of its poisonous nature, emerald green is still largely used. All possible shades of green can be produced from it, yellowish-green or pale green, by admixtures of yellow pigments, such as chrome yellow, or white pigments, such as barytes or white lead. Many qualities of green known as palette green, Basle green, etc., are generally composed of such mixtures. ”

“ They must provide themselves with absolute indigo, by an expensive and troublesome process, not suited to the busy bleacher. The vitriolage, as the French term it, or the souring of the English bleacher, consists in immersing the goods for four hours in dilute sulphuric acid, containing one gallon of oil of vitriol to from 25 to 30 of water, thoroughly intermixed by stirring; for the density of the acid is an obstacle to its equal distribution through the water. This dilute acid will have a density of from 1·047 to 1·040, and will contain from 7 to 61⁄2 per cent. ”

“ The only simple green of a tolerable degree of brightness, is verdigrease, or its different preparations: though far from being durable, it may be rendered more so, as a water-colour, by dissolving it in the pure tartarous acid.—A green colour may be made by compounding Prussian, or other blue, with yellow ”

“ It is often perceived that certain rose-red flowers, as those of the Mallow, and in particular those of the Hibiscus Syriacus, acquire by fading a blue and then a green coloration, which change, as we have found, depends on the decomposition of an organic nitrogenous substance, which is found very frequently in the petals. This body generates as it decomposes ammonia, which communicates to the flowers the blue or green color. By action of weak acids, the petals can be restored to their rose-red color. ”

“ Another Experiment.
Heat some blue vitriol (sulphate of copper) in an iron ladle till all the water contained in the crystals is driven off, and the color changes to a gray. Take the lumps out without breaking them, and lay the dried blue vitriol on a plate. If this be moistened with water steam is produced; and if a slice of phosphorus is then laid on the sulphate of copper it ignites, demonstrating again that the condensation of a liquid produces heat. The addition of the water restores the blue color, thus proving that water was necessary to the composition of blue vitriol. ”

“ Water being a colorous fluid ought, one would imagine when mixed with other substances of no decided color, to produce a colorless compound. Nevertheless, it is to water only that blue vitriol or sulphate of copper owes its vivid blueness, as will be plainly evinced by the following simple experiment. Heat a few crystals of the vitriol in a fire-shovel, pulverize them, and the powder will be of a dull and dirty white appearance. Pour a little water upon this [44] when a slight hissing noise will be heard, and at the same moment the blue color will instantly reappear. ”

“ Bluish or violet color, accompanied by a flavor of the lees, often occurs in wines of southern countries, and is due to an abundance of coloring matter and a lack of tartaric acid. When the violet-colored wine has a good deal of color, and more than nine per cent. of alcohol, the color may be changed to red by mixing with it from one-sixth to one-fourth of green wine, which contains an excess of tartaric acid, the natural blue color of the grape being changed to red by the action of the acid ”

“ Sleeping with the windows closed in a room newly painted has produced fatal diseases. To some lungs the vapour of white lead is poisonous. To none is it quite innoxious. Its dangerous properties may be neutralized by placing in newly-painted rooms, large tubs of water, into each of which has been mixed an ounce of vitriol. The tubs must be set near the walls, and the water and vitriol renewed every day. ”

“ We should have done the horrid thing at night and let it work while we all slept in the tents, but the chemist warned us not to dream of attempting it in anything like dusk or darkness. Each person has to be told off to stand ready in one room with their allowance of vitriol, and the prussic acid safely fastened up in a paper bag, tied at the mouth with a long piece of string, so that you can drop it into the vitriol and get away before the fumes suffocate you ”

“ Hellot observed that by increasing the quantity of the Vitriolic Acid he obtained more of this Oil, and less of the Ardent Spirit containing the Æther. The reason is this: the more Oil of Vitriol you put in the mixture, the more Spirit of Wine must be totally decomposed, and consequently the more of this Oil will be obtained; which, as we have shewn, is one of the principles resulting from the decomposition of Spirit of Wine. ”

“ The evolution of chlorine is promoted by occasionally renewing the exposed surface, by stirring it with a piece of stick, and after it becomes scentless, by the addition of a little acid, as strong vinegar, or hydrochloric acid, or oil of vitriol, largely diluted with water. ”

“ When united they form water, which is universally employed to extinguish fire. Blue vitriol is blue, as the name implies, yet it is composed of four elements, two of which, H and O, are colorless, copper, which is red, and sulphur, which is yellow. Sulphur has little or no odor, and hydrogen has none, but when united they form a gas which has the odor of spoiled eggs. White sugar is nothing but black charcoal and water. It will thus be seen that here is a source of new things in nature. Whatever chemical affinity touches is changed. ”

“ It is non-granular, covers well, mixes with water or oil, and is a good artists’ colour for sky effects. It is permanent in strong sunlight and impure atmosphere, and resists acids and alkalies at normal temperatures. Hot hydrochloric acid dissolves it, and addition of water to the pale blue solution produces a violet red; evaporation to dryness restores the original pigment. The green tint of a nitric acid solution is due to iron and nickel impurites. ”

“ The compound is to be dissolved in water of dew, the solution filtered and abstracted in a glass alembic three times until the greenness turns to a black like ink, “stinking like a carcase.” After standing for forty hours the blackness and stink will depart, leaving a milky white solution. This is to be dried to a white mass, which will change into divers colours, ultimately becoming a finer green than formerly. That green gold is to be dissolved in spirit of wine, to which it will impart a quintessence, red as blood, which is the quickening tincture, a superfluous ashy body being left. ”

“ Coloring Perfumes.—Chlorophyll is a suitable agent for coloring liquid perfumes green. Care must be taken to procure an article freely soluble in the menstruum. As found in the market it is prepared (in form of solutions) for use in liquids strongly alcoholic; in water or weak alcohol; and in oils. Aniline greens of various kinds will answer the same purpose, but in a trial of any one of these it must be noted that very small quantities should be used, as their tinctorial power is so great that liquids in which they are incautiously used may stain the handkerchief. ”

“ First, at least three earthy salts-the sulphates of lime, alumina, and potassa. Second, two organic and one simpler acid—acetic (absolute vinegar) , meconic (one of the most powerful irritants which can be applied to the intestines through the bile) , and sulphuric. All these exist uncombined in the gum, and free to work their will on the mucous tissues.
A green extractive matter, which comes in all vegetal bodies developed under sunlight, next deserves a place by itself, because it is one of the few organic bodies of which no rational analysis has ever been pretended. ”