AXILIXE, OR COAL-TAR COLORS. 



at Cambridge, Oxford, and Manchester. The 

 Bishop of Gloucester and Bristol was the pres- 

 ident ; and among the distinguished members 

 who attended, were the Bishops of Chichester, 

 Ely, Bath and Wells, Kilmore, Guyana, the 

 Earl of llarrowby. Lord Lyttleton, Mr. Beres- 

 ford Hope. Archdeacon Denison, Dr. Pusey, 

 Canon M'Xeile. All parties were again repre- 

 sented, though the High Church party was ob- 

 viously in the ascendency. On several impor- 

 tant topics, as the increase of the episcopate 

 and the restoration of church synods, all the 

 speakers were agreed, thus indicating clearly 

 the current of public opinion in the Church of 

 England. 



AXILIXE, OB COAL-TAR COLORS. Pur- 

 chasers of textile fabrics, and especially of silks, 

 have within a very few years past found the 

 market supplied with such goods dyed in a va- 

 riety of unusually brilliant and beautiful colors 

 and hues of color (violets, crimsons, blues, tc.), 

 some of them unlike any before obtained in 

 dyed fabrics, and in regard to all of which very 

 little has been generally known, further than 

 that the new dyes were produced from coal-tar. 

 It was, iu fact, only so late as the year 1856 

 that a product capable of yielding a permanent 

 color, and so of being used as a dye, was ob- 

 tained from coal-tar ; this was the discovery of 

 Mr. H. AV. Perkin, and the color produced was 

 known at the first as mairce, or Per Jan 1 * purple. 

 In the brief period intervening since that time, 

 however, the production and application of the 

 new dyes have given rise to large and import- 

 ant branches of industry ; and the history of 

 the subject, traced from its two starting-points, 

 in the discovery of lenzole by Faraday, in 1S25, 

 and of the so-called " crystalline " by Unver- 

 clorben in 1826, affords, as has been well said, 

 a remarkable instance of the manner in which 

 abstract scientific research becomes, in the 

 course of time, of the most important practical 

 service." 



Brief references to the aniline colors occur 'in 

 the two preceding volumes of this CYCLOPE- 

 DIA, under the head of CHEMISTRY. The reader 

 may profitably consult, iu connection with the 

 subject, the articles COAL PEODUCTS, XAPHTHA, 

 BEXZOLE, and AXILIXE, in the XEW AMERICAN 

 CYCLOPEDIA. The chemical processes requisite 

 for producing the aniline dyes, and other re- 

 lated substances to be mentioned, will not here 

 be given in detail ; the reader is referred for 

 such information to the works upon practical 

 chemistry, and upon dyeing. 



Aniline was first obtained in separate form 

 by L'nverdorben, in 1826. He isolated it from 

 among other products of the distillation, of ani- 

 mal matters, as a heavy but volatile oily liquid, 

 which he named crystalline. Later it was pro- 

 duced by Fritsche, of St. Petersburg, by the 

 action of caustic potash on indigo. After this, 

 Zinin, of St. Petersburg, by a process consisting 

 essentially in acting upon nitre-benzole with 

 sulphide of ammonium, produced the same 

 body, wiiich he named " bemidum." And still 



later an oily liquid was at different times sepa- 

 rated from among the products of the distilla- 

 tion of coal-tar, by M. Runge, Prof. A. TV. Hof- 

 mann, and others, and which was observed, 

 when brought in contact with bleaching pow- 

 der (chloride or hypochlorite of lime), to de 

 velop a beautiful violet blue, that, however, 

 soon disappeared. Among the names which 

 different experimenters gave to this body wero 

 also those of l-yanol, phenylamine, and phena- 

 mide. To Hofmann, it appears, is due the 

 credit of proving the identity of the substance, 

 as thus obtained from different sources by so 

 many different chemists. This he was enabled 

 to do, and at the same tune to determine the 

 composition of the body, by his study of it as 

 obtained from isatine (oxidized indigo-blue), 

 heated in mixture with potash. As thus ob- 

 tainable from indigo (Spanish, afrit), Hofmann 

 gave to this substance the name of aniline, 

 and this name, as being most convenient for 

 the formation of the compound terms needed 

 for the many derivatives of the substance itself, 

 has since become generally adopted. Besides 

 the sources already named, aniline can be ob- 

 tained by certain reactions from many other 

 bodies, most of them in fact derivatives from 

 coal-tar, as salicylamide, nitrotoluole, &c. ; but 

 of the methods and sources thus far named, by 

 far the greater number are as yet of interest to 

 the theoretical chemist only. Indeed, during 

 all the period now considered, and up to the 

 time of Mr. Perkin's discovery of maute, ani- 

 line still remained a subject of scientific interest 

 and curiosity only ; and even at the time when 

 this important discovery was made, both ani- 

 line and the nitro-benzole from which its 

 manufacture oa the large scale is now carried 

 on, were as yet to be met with only in small 

 quantities in the laboratory. 



In the early part of 1856, Mr. Perkin was 

 experimenting on a compound of toluidine. in 

 the hope of forming quinine artificially. Fail- 

 ing in this, he tried the action of bichromate of 

 potash, acidulated with sulphuric acid, on the 

 sulphate of aniline. The result was a black 

 precipitate of unpromising appearance, but 

 which, on examination, was found to yield the 

 dye already mentioned. This, known as ma '.'.re. 

 phenamine, indisine, fcc., is more correctly 

 termed aniline purple, or, as some dealers pre- 

 fer to say, aniline violft. The interest created 

 by the introduction of this new color naturally 

 directed the attention of chemists again to its 

 source. Prof. Hofmann, in a note to the Royal 

 Society, June, 1858, mentioned the formation 

 of a crystalline derivative from aniline, by ac- 

 tion on the latter of bi-chloride of carbon, the 

 reaction being accompanied by the appearance 

 of a magnificent crimson color. This appears 

 to have been the first notice of the anilint crim- 

 son (aniline red), subsequently named by its 

 discoverer rosaniline ; although it is also stated 

 that Xatanson had observed this coloring mat- 

 ter, as formed from aniline, in 1856. As, how- 

 ever, very little of the pigment was obtained 



