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DYEING AND CALICO PRINTING.
19. Methyl-diphenylamine Violet.—Place upon copper plates arranged
in a stove heated by steam—
Hydrochlorate of methyl-benzyl-phenylamine .. 3 kilos.
Sulphate of copper. 1 kilo.
Chlorate of potash. 0'2 „
Siliceous sand . 20 kilos.
Hydrochlorate of essence of terebenthin .. .. 2 „
The stove must be so arranged as to permit of a free circulation of air. Anexcess of moisture is kept up by the injedtion of a little steam, and themixture is frequently stirred. The temperature is maintained at 45 0 to 70° C.The operation is considered at an end when nothing more of an oily nature isperceived. The produdt is then repeatedly extradted with boiling water, whichtakes up the soluble metallic salts. In order to dissolve the colouring mattermixed with the sand either alcohol or strong hydrochloric acid may be used.When the sand is exhausted all the coloured solutions are mixed anddistilled if alcohol has been used, or diluted with water and precipitated withcommon salt if hydrochloric acid has been employed. The colour thusobtained is transmuted into a base by means of soda or potash. The base iswashed with water and taken up with acetic or hydrochloric acid. Thesesalts are very soluble and dye blue-violets.
Others of the mixed tertiary monamines, as methyl-diphenylamine, benzyl-diphenylamine, benzyl-phenyl-toluylamine, and benzyl-ditoluylamine yieldsimilar colours.
20. Paris Green.—Poirrier, Bardy, and Lauth prepare this new greencolour by adting with an oxidiser—such as bromine, iodine, chlorine, weaknitric acid, nitrates of mercury copper and other metals, and solution ofchloride of iodine in ten times its weight of water—upon benzyl- or dibenzyl-aniline, tolyl- or ditolyl-aniline, benzyl- or dibenzyl-toluidine, tolyl- or ditolyl-toluidine, and their mixtures.
21. Mefhylaniline Green.—This colour, which is generally replacingiodine green, is prepared by causing nitrate of methyl to read! upon Poirrier’sviolet (methylaniline violet). The separation of the violet and greencolouring matters is effedled by the addition of a solution of chloride of zincand gradual saturation with carbonate of soda. A zinc-violet lake is throwndown at first. When all the violet is precipitated and filtered off, the filtrateis concentrated and allowed to cool, when a double chloride of zinc andaniline green crystallises out.
22. French Yellow; Chryseic Acid (Nitro-xynaphthalic Acid ofDusart and Gelis).—If 100 parts of nitro-naphthalin are intimately mixedwith 250 parts of dry hydrate of lime, and the mixture moistened with75 parts of hydrate of potash dissolved in as little water as possible, and thewhole heated for ten to twelve hours to the temperature of 150° C. in an oil-bath with free excess of air, or preferably in a current of oxygen, the mixturebecomes oxidised and assumes gradually a deep yellowish-red colour. Ontreating the mass with hot water and filtering the liquid, we obtain a yellowsolution of the nitro-xynaphthalate of potash, and after sufficiently concentratingthe liquid, the nitro-xynaphthalic acid maybe precipitated by the addition of anystrong acid, in the form of fine yellow flocks, soluble in hot water, alcohol,wood-spirit, and acetic acid. It dyes silk and wool a full golden yellow.