548 Royal Society : — 



other bases, most of them amorphous and accessible only in the form 

 of platinum-salts, are produced, and complicate, owing to the simi- 

 larity of their chemical characters, the purification of the new com- 

 pound. Notwithstanding many efforts, I failed in obtaining the 

 new colouring matter in a state fit for analysis, and for the time 

 abandoned the inquiry. 



Industry, however, was not long in discovering new and much 

 more appropriate methods for the production of the crimson aniline 

 dye. Certain metallic chlorides (tetrachloride of tin) and nitrates 

 (mercurous nitrate), and numerous oxidizing agents are capable of 

 converting aniline into the crimson colouring matter. It was M. 

 Verguin who first prepared this colour upon a large scale by the 

 action of tetrachloride of tin on aniline. Since that time the pro- 

 duction of the aniline-crimson has become an important industry, 

 which, in the hands of Messrs. Simpson, Maule, and Nicholson in 

 this country, of Messrs. Renard freres in France, has rapidly attained 

 to colossal proportions. The interest attached to the subject is suffi- 

 ciently evident by a glance at the periodical literature of the day. 

 The journals of applied chemistry teem with the descriptions of pro- 

 cesses for the production of the aniline-crimson, for which the names 

 fuchsine, magenta, and others more fanciful have been proposed. 

 Even the action of tetrachloride of carbon on aniline, little promising 

 as it appeared at first, has been used upon the large scale ; and in- 

 teresting papers upon the industrial production of the colour by this 

 process have been published by M. Charles Dolfus Galline*, by 

 Messrs. Monnet et Duryf, and lastly by M. LauthJ, who have 

 proved that aniline-crimson, prepared upon the large scale by means 

 of tetrachloride of carbon, may be applied in dyeing with exactly the 

 same result as the colouring matter produced by other processes. It 

 i§ not the object of this Note to enter into a detailed account of the 

 development of this new industry, which has been admirably traced 

 by M. E. Kopp in a series of interesting articles published in the 

 c Repertoire de Chimie Appliquee ; ' but I thought it right to quote 

 the above authorities in order to show that the basic colouring matter 

 obtained by me in 1858, while studying the action of tetrachloride 

 of carbon upon aniline, is identical with the aniline-crimson which is 

 now by various processes manufactured upon an enormous scale. 



A substance possessing such remarkable properties as aniline- 

 crimson, and accessible, moreover, as a commercial product, could 

 not fail to attract the attention of scientific inquirers. The subject 

 has been examined in succession by M. Guignet §, M. Bechamp ||, M. 

 Wilm^[, Messrs. Persoz, De Luynes et Salvetat**, M. Schneiderff, 

 and more recently by M. Emile Kopp % % and M. Bolley§§. The 

 conclusions, however, at which these experimentalists have arrived 

 are far from concordant. I attribute this discrepancy in the results 



* Repertoire de Chimie Appliquee, 1861, p. 11. f Ibid. p. 12. 

 % Ibid. p. 416. § .Bull. Soc. Chira. Seance du 23 Dec. 1859. 



|| Annales de Chim. et de Phys. [3] tome lix. p. 396. 

 «if Bull. Soc. Chim. Seance du 27 Juillet 1861. 

 ** Comptes Rendus,'li. 538. ft Ibid. li. 1087. 



++ 



Annates de Chim. et de Phys. tome xii. p. 222. 



§§ Dingier's Journal, clx. 57. 



