218 ANILINE AND ANILINE

Thus Laurent and Castiielaz prepared a reddye, termed by them Erythrobenzol, by acting onnitrobenzol with iron filings and hydrochloric acid,and heating the mass. Probably the colouring matterwas identical with fuehsino, being formed by adouble reaction, viz. :—First, the action of themetallic chloride on the aniline, analogous to thatof the tin tetrachloride; and secondly, the reactionof nitrobenzol on aniline, in which fuchsine is alsoformed. This latter process has been several timespatented since by other chemists, and quite recentlyby Meister Lucius and Brbning, who are nowworking it on a large scale. Schlumberger proposedthe use of corrosive sublimate and tin amalgam;Depouilly and Lautii utilized the reaction ofaniline nitrate on aniline (several patents involvingthis reaction have been subsequently taken out);Blockley, Watson, and other chemists employedaqua regia in some form as an oxidizing agent;Gingon used gaseous chlorine; Mene nitric acid;Jacquemin ferric sulphate; Williams used mer-curic phosphate or acetate; Dale and Caro amixture of lead nitrate and phosphoric acid; Smithused antimonie anhydride; Gratrix a nitrate ofantimony (i.e., a mixture of antimonie oxide andnitric acid) or nickel nitrate; others heated anilinesalts either per se or in contact with sand (probablythe oxygen of the air was here the oxidizing agent).Wilson heated aniline with 5 per cent, of arsenic,nitric, or iodic acid to 120° C., and then graduallyadded manganese dioxide; whilst recently Feiirierehas obtained a rod dyestuff by the action on anilineacetate of an ammoniacal copper solution; and Clacsand also Hamel have obtained a similar product byheating aniline with sulphur chloride.

All these processes, however, and others too numer-ous to mention in detail, have been practically foundinferior for commercial purposes to the method nowin general use, viz., that patented almost simultane-ously, in England by Medlocic and by Nicholson,and in France by Girard and De Laire ; i.e., theuse of arsenic acid as a dehydrogenizing agent.

Medlock’s patent was dated January 18, 1860;Nicholson’s, January 26, 1860 (both in GreatBritain ) ; Girard and De Laire’s was dated May26, 1860 (France ). Arsenic acid, however, had beenpreviously mentioned as a fuchsine-producing agentin a patent specification of Geriier-Keller in 1859,and had been described by Bechamp in the latterend of 1850. Poulain patented in 1869 the indirectoxidation of aniline and its homologues by means ofchlorination and heating.

Various preparations are met with in the trade,designated as cerise, maroon, &c., which are mainlyimpure fuchsine; for the most part these are extractedfrom residues and bye products of the manufacture.

B. Rouge de toluene, and C. Xylidine red, wereintroduced by Coupier in 1866, and are as yet butlittle known.

I). Chrysaniline and chnjmtoluidine red.

E. Oxidation and decomposition products of rosaniline,gcranosine. F. Sajfranine. G. URicks' scarlet, patentedin 1869. II. Rosolic acid.

DYES.— Bed and Blue Dyes.

1. Furfurol red .— Stenhouse found in 1860 thatwhen aniline acetate and furfurol are well mixedtogether at the ordinary temperature, a red colouringmatter is formed, insoluble in water, but soluble inalcohol, wood spirit, and strong acetic acid. Ammoniadissolves it to a colourless liquor, which is reddenedagain by acids. It dyes silks and woollens of a finered tint, but it is very unstable, and cannot resist theaction of light, and even fades when kept in the dark.Attempts were made to manufacture it by Persoz,but without success. Toluidine forms a similar pro-duct (Stenhouse—Proc. Boy. Soc., xviii. p. 537).

2. Blue Dyes. —A. Various. — Fritsche found in1840 that when aqueous aniline salts are treated withhydrochloric acid and potassium chlorate, indigo blueflakes are precipitated; in 1860, Calvert, Lowe,and Clift, utilized a similar reaction for the pre-paration of a blue dye, called by them Azurine, bythe action of weak soda or soap solutions on goodsprinted with emeraldine.

Caro found that blue products were formed bythe reaction of nitrous acid on fuchsine, and the par-tial reduction of the products ; and Lautii observedin 1860 that blue bodies result from the action ofhydrogen dioxide on aniline salts, or of certain re-ducing agents, such as stannous chloride, on rosanilinesalts. These substances are probably closely alliedto the two following dyestuffs.

Midlwuse Blue and Aldehyde Blue .—The formerof these was obtained in 1861 by Gros Benard andSchaeffer by boiling together rosaniline nitrate,powdered shellac, carbonate of soda, and aqueousalcohol; the latter in 1860 by Lautii, being producedwhen an aldehyde, or a mixture of materials thatwill generate aldehyde, is made to act on a hot acidsolution of aniline. The want of permanency of thesedyes has led to their almost entire disuse ; although,unlike most aniline colours, they possess the power ofadhering to cotton without mordanting.

The fugitive blue, or violet blue, formed by theaction of hypochlorites on aniline (Bunge’s reaction),and various blues of a more or less purplish cast,formed by various inventors who endeavoured toimitate Perkin’S mauve, are probably related to thesesubstances ; their industrial importance is small, andof their chemical composition nothing whatever isknown, save that Bunge’s blue is closely allied tomauveine, as it gives rise to that substance on boilingwith alcohol (Perkin). Guignon Marnas and Bon-net have prepared a blue aniline derivative, Azuline,by heating coralline ( q. v.) with aniline.

B. Phenyl and Toluyl Substitution Derivatives of Fuch-sine .—Soon after the publication of the arsenic acidprocess for making fuchsine, it was noticed that bythe use of an insufficient quantity of acid (less thanone equivalent for one of aniline) violet and evenblue products were obtained instead of red. Thus,in 1861, Girard and De Laire patented the use of amixture of 1 part acid and 1$ to 2 parts aniline forthe production of violet and violet blue dyestuffs ; ina later patent the action of aniline on a ready formedrosaniline salt was specified for the same purpose, thefirst product being a violet dye, which by further