Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 257

Mr Nicholson, by treating Lyons blue in the same manner as indigo is converted into sulphindigotic acid, has succeeded in rendering it soluble; dissolving in alkalies to form colourless salts, and decomposed by acids into its original blue colour.

By a modification of this method 'NICHOLSON'S BLUE' is prepared, a fine soluble blue dye. Another colouring matter called Paris blue or bleu de Paris was obtained by heating stannic chloride with aniline for 30 hours at a temperature of 356 Fahr. (180 C.). It is a fine pure blue, soluble in water, and crystallising in large blue needles with a coppery l.u.s.tre.

Another method pursued in manufacture of this colour on a large scale is carried out by allowing a mixture of a salt of rosaniline, with an excess of aniline, to digest at a temperature of 150 to 160 for a considerable time. If a mixture of 2 kilogrammes of dry hydrochlorate of rosaniline, and 4 kilogrammes of aniline be employed, the operation is completed in four hours. The crude blue is purified by treating it successively with boiling water, acidulated with hydrochloric acid, and with pure water, until it is of the purest blue colour. 'Nicholson's blue' is obtained by digesting triphenyl rosaniline--mono-sulphonic acid (made by dissolving triphenyl rosaniline hydrochloride in strong sulphuric acid, and heating the solution for five or six hours. On the addition of water, the acid is obtained as a dark blue precipitate, and dried at 100), with a quant.i.ty of soda-lye not quite sufficient for saturation, filtering the solution and evaporating. It is dried at 100. Wool dipped into a hot aqueous solution of Nicholson's blue, especially if borax or water-gla.s.s be added, extracts it in a colourless state, and holds it so fast that it cannot be washed out with water, but on dipping the wool thus prepared into an acid the salt is decomposed, and the colouring matter is set free.

ANILINE BLUE FOR PRINTING. Blumer-Zweefel gives the following process:--"Mix 100 parts of starch with 1000 parts of water, and add to it while warm 40 parts of pota.s.sium chlorate, 3 to 4 parts of ferrous sulphate, and 10 parts of sal ammoniac. The well-mixed paste, when quite cold, is mixed with 70 parts of aniline hydrochloride, or an equivalent quant.i.ty of tartrate, and immediately used. The printed goods are oxidised, then pa.s.sed through warm or faintly alkaline water, whereby the blue colour is developed."

VIOLET IMPERIAL. If the action of the aniline and magenta in the process of manufacturing aniline blue be stopped before it is finished, and the resulting product treated with dilute acid, a colouring matter called violet imperial is obtained. It is now, however, replaced by the Hofmann violets.

Mr Nicholson obtains another violet from aniline red, by heating it in a suitable apparatus to a temperature between 200 and 215 C. The resulting ma.s.s is exhausted with acetic acid, and the deep-violet solution diluted with enough alcohol to give the dye a convenient strength. Aniline violet, although it resists the action of light to a very considerable extent, has been shown by Chevreul to be inferior in this particular than either madder, cochineal, or indigo.

HOFMANN VIOLETS. On a large scale these violets are produced in deep cast-iron pots, surrounded by a steam jacket, and provided with a lid, having a perforation for distilling over the excess of reagents.

These vessels are charged with a solution of magenta in methylated or wood spirit, and iodide of ethyl or methyl, in proportions according to the shade required, and the whole heated by steam for five or six hours, when the excess of alcohol and iodide of ethyl is distilled over. The resulting product is dissolved in water, filtered, precipitated with common salt, and well washed.

Like most of the other colours, Hofmann violets are salts of colourless bases. That of a red shade has a formula of C_{22}H_{23}N_{3}, or C_{20}H_{18}(C_{2}H_{5})N_{3}; of a true violet shade C_{24}H_{27}N_{3}, or C_{20}H_{17}(C_{2}H_{5})_{2}N_{2}; and of a blue shade of violet, of C_{26}H_{31}N_{3}, or C_{20}H_{16}(C_{2}H_{5})_{3}N_{3}. They are all moderately fast on wool and silk, although less so on cotton, and, as they can be produced in nearly every shade of violet, are in great use, having replaced most of the other violets.

The following processes have also been proposed for the production of aniline violet:

1. Oxidation of an aniline salt by means of a solution of permanganate of pota.s.sium. (Williams.)

2. Oxidation of an aniline salt by means of a solution of ferricyanide of pota.s.sium. (Smith.)

3. Oxidation of a cold and dilute solution of hydrochlorate of aniline, by means of a dilute solution of chloride of lime. (Bolley, Beale, and Kirkmann.)

4. Oxidation of a salt of aniline by means of peroxide of lead under the influence of an acid. (Price.)

5. Oxidation of a salt of aniline in an aqueous solution of peroxide of manganese. (Kay.)

6. Oxidation of a salt of aniline by free chlorine or free hypochlorous acid. (Smith.)

DAHLIA. This is prepared from mauve and iodide of ethyl, in the same manner as the Hofmann violets, and is a purple-red violet. It is a good colour, but the expense precludes its general use.

BRITANNIA VIOLET. This is obtained in the same manner as the Hofmann violets, by acting on an alcoholic solution of magenta, with a thick, viscid, oily fluid of the formula C_{10}H_{15}Br_{3}, obtained by cautiously acting with bromine on oil of turpentine. It is a beautiful violet, capable of being manufactured of every shade, from purple to blue, and most extensively used.

ALDEHYDE GREEN. Prepared by dissolving one part of magenta in three parts of sulphuric acid, diluted with one part of water, adding by degrees one and a half part of aldehyde, and heating the whole on a water bath until a drop put in water turns a fine blue. It is then poured into a large quant.i.ty of hot water containing three parts of hyposulphite of sodium, boiled and filtered. The filtrate contains the green, which can either be kept in solution or be precipitated by means of tannic acid or acetate of sodium. Like the other colours, this green is a salt of a colourless base, containing sulphur, the formula of which is not known, and is princ.i.p.ally used for dyeing silk, being very brilliant in both day and artificial light.

IODIDE GREEN. Produced during the manufacture of the Hofmann colours, and is now used for dyeing cotton and silk; its colour being bluer than that of aldehyde green, it is more useful. Iodide green, not being precipitated by carbonate of sodium, is usually sold in alcoholic solution.

PERKINS GREEN. This is also a magenta derivative, and a salt of a powerful colourless base. It resembles the iodide green, but is precipitated by alkaline carbonates and picric acid. This colour is used chiefly for calico printing, and is quite as fast as the Hofmann colours.

ANILINE GREEN. When treated with chlorate of pota.s.sium, to which a quant.i.ty of hydrochloric acid has been added, aniline a.s.sumes a rich indigo-blue colour. The same result occurs if the aniline be treated with a solution of chlorous acid. Similar blues have been obtained by Messrs Crace Calvert, Lowe, and Clift. Most of these blues possess the property, when subjected to the action of acids, of acquiring a green tint, called EMERALDINE. Dr Calvert obtained this colour directly upon cloth, by printing with a mixture of an aniline salt and chlorate of pota.s.sium, and allowing it to dry. In about twelve hours the green colour is developed.

This colour may be converted into blue by being pa.s.sed through a hot dilute alkaline solution, or through a bath of boiling soap.

ANILINE YELLOW. Amongst the secondary products obtained during the preparation of aniline red, there occurs a well-defined base of a splendid yellow colour, to which the name _chrysaniline_ has been given. It is prepared by submitting the residue, from which the rosaniline has been extracted, to a current of steam for some time, when a quant.i.ty of the chrysaniline pa.s.ses into solution. By adding nitric acid to the solution, the chrysaniline is thrown down in the form of a difficultly soluble nitrate. The intimate relation between chrysaniline, rosaniline, and leucaniline has been shown by Hofmann.

Chrysaniline C_{20}H_{17}N_{3}.

Rosaniline C_{20}H_{19}N_{3}.

Leucaniline C_{20}H_{21}N_{3}.

SAFFRANINE. This dye stuff is of a bright red-rose colour. Mene says it may be prepared commercially by treatment of heavy aniline oils successively with nitrous and a.r.s.enic acids; or two parts of the aniline may be heated with one of a.r.s.enic acid, and one of an alkaline nitrate for a short time, to 200 or 212 F. The product is extracted with boiling water, neutralised with an alkali, filtered, and the colour thrown down by common salt.

Besides the above products obtained from aniline, a series of colours have been obtained from phenol, or carbolic acid, another substance obtained from coal tar.

PICRIC ACID. This is obtained by treating in a suitable apparatus, with proper precautions, carbolic acid with nitric acid. It is a pale yellow crystalline acid, forming dark orange explosive salts, and dyeing silk a fine yellow.

ISOPURPURATE OF POTa.s.sIUM. GRENATE BROWN. GRENATE SOLUBLE. By treating picric acid with cyanide of pota.s.sium a very explosive salt is obtained, used to dye wool a dark maroon colour.

AURINE, or ROSOLIC ACID. This is obtained by heating a mixture of sulphuric, oxalic, and carbolic acids, and purifying the products. It is a beautiful reddish, resinous substance, with a pale green l.u.s.tre, and yielding an orange coloured solution, changed by alkalies to a splendid crimson. Owing to the difficulty in using it, however, it is not very extensively employed.

PEONINE, or CORALLINE. This dye is formed when rosolic acid and ammonia are heated to between 248 and 284 Fahr. (120 to 140 C.). It is a fine crimson dye, forming shades similar to safflower on silk, but, owing to the bad effects of acids, not much used.

AZULINE. Prepared by heating coralline and aniline together. A coppery coloured resinous substance, soluble, in alcohol, and with difficulty in water, and dyeing silk a blue colour. The aniline blues, however, have superseded it to a great extent.

There are other substances obtained from coal tar that have been employed to form dyes, but of which we shall only refer to one--naphthaline. By treating this in exactly the same manner as benzol, it is converted into aniline. A solid crystalline white base, termed naphthylamine, is produced. From this substance is obtained the following dye.

DINITRONAPHTHAL, or MANCHESTER YELLOW. Naphthylamine is converted into diazynaphthol by treatment with nitrate of pota.s.sium, and the latter, when heated with nitric acid, yields the colour. It is a weak acid, and the salt employed in commerce is the beautiful yellow crystalline calcium salt which dyes silk and wool a magnificent golden-yellow colour.

=TARPAU'LIN.= _Syn._ TARPAWLING. Canvas covered with tar or any composition to render it waterproof.

=TAR'RAS.= _Syn._ TERRAS. A volcanic product resembling puzzolano, that imparts to mortar the property of hardening under water. Several other argillo-ferruginous minerals possess the same power, and are used under this term.

=TAR'TAR.= _Syn._ ARGAL, ORGOL; TARTARUM, TARTARUS, L. Impure bitartrate of pota.s.sa. Crude tartar is the concrete deposit formed upon the sides of the casks and vats during the fermentation of grape juice. That obtained from white wine is white argol; that from red wine, red argol. After purification it forms cream of tartar.

=Tartar, Ammo"niated.= _Syn._ AMMONIO-TARTRATE OF POTa.s.sA, SOLUBLE TARTAR (Ammoniated); TARTARUS AMMONIATUS, TARTARUM SOLUBILE AMMONIATUM, L.

_Prep._ Neutralise a solution of cream of tartar with ammonia in slight excess, then evaporate, and crystallise. Very soluble in water. A favourite laxative on the Continent.

=Tartar, Bo"raxated.= _Syn._ SOLUBLE CREAM OF TARTAR, BORO-TARTRATE OF POTa.s.sA AND SODA; TARTARUM BORAXATUM, CREMOR TARTARI SOLUBILIS, POTa.s.sae ET SODae TARTRAS BORAXATA, L. _Prep._ From borax, 2 lbs; cream of tartar, 5 lbs. (both in powder); dissolved in water, evaporated, and crystallised.

See POTa.s.sIUM BOROTARTRATE.

=Tartar, Chalybea'ted.= Pota.s.sio-tartrate of iron.

=Tartar, Cream of.= Bitartrate of pota.s.sa.

=Tartar, Emet'ic.= Pota.s.sio-tartrate of antimony.

=Tartar, Oil of.= Deliquesced carbonate of pota.s.sa.

=Tartar, Reduced.= _Syn._ CREMOR TARTARI REDUCTUS, L. An article is sold, under the name of 'British cream of tartar,' which contains 1/4 its weight or more of bisulphate of pota.s.sa.

=Tartar, Salt of.= Carbonate of pota.s.sa.

=Tartar, Sol'uble.= Neutral tartrate of pota.s.sa.

=Tartar, Spirit of.= Pyrotartaric acid.

=TARTAR'IC ACID.= H_{2}C_{4}H_{4}O_{6}. _Syn._ ACID OF TARTAR, ESSENTIAL SALT OF T.; ACIDUM TARTARIc.u.m (B. P., Ph. L., E., & D.), SAL ESSENTIALE TARTARI, L. _Prep._ 1. (Ph. L. 1836.) Take of cream of tartar, 4 lbs.; boiling water, 2 gall.; dissolve by boiling; add, gradually, of prepared chalk, 12 oz. 7 dr. (made into a milk with water), and, when the effervescence ceases, add another like portion of prepared chalk, dissolved in hydrochloric acid, 26-1/2 fl. oz., or q. s., diluted with water, 4 pints; collect the precipitate ('tartrate of lime'), and, after well was.h.i.+ng it with water, boil it for 15 minutes in dilute sulphuric acid, 7 pints and 17 fl. oz.; next filter, evaporate the filtrate (to the density of 138), and set it aside to crystallise; redissolve the crystals in water, concentrate the solution by evaporation, and recrystallise a second and a third time. The Edinburgh formula is nearly similar. In the Ph. L. & D. tartaric acid is placed in the Materia Medica.

2. (Gatty.) The solution of argol or tartar is first neutralised with carbonate of pota.s.sa, and to every 300 gall. of the clear liquid, at 5 Twaddell, 34 gall. of milk of lime (1 lb. of lime per gall.) are added; carbonic acid gas is then forced in, with agitation; decomposition ensues, with the formation of 'bicarbonate of pota.s.sa' and 'tartrate of lime,' the last is converted into tartaric acid in the usual manner, and the former is evaporated in iron pans, and roasted in a reverberatory furnace for its pota.s.sa.