1862.] on Mauve and Magenta. 479 



in the dry state and in solution. This brown lump, with the remark- 

 able coppery lustre, is Mauve in the solid state ; its extraordinary 

 tinctorial powers will be appreciated, if I tell you that this beautiful 

 violet-coloured solution contains not more than t^ of a grain of Mauve 

 in one gallon of alcohol ; you will also understand the considerable 

 commercial value of this substance. Weight for weight, I am told by 

 Mr. Perkin, this colouring matter, when pure, is sold at the price of 

 metallic platinum. 



Very little is known regarding the chemical nature of Mauve ; its 

 composition is not yet made out, and as a matter of course the process 

 by which it is formed from aniline remains as yet perfectly unex- 

 plained. 



Magenta is one of the fancy names given to the splendid crimson, 

 which is likewise generated from aniline by the action of oxidizing 

 agents. This substance was first observed in purely scientific researches, 

 and more especially in the action of tetrachloride of carbon upon 

 aniline. To a French chemist, M. Verguin, the merit is due of having 

 for the first time obtained this substance on a larger scale ; he pro- 

 duced it by the action of tetrachloride of tin on aniline. Numerous 

 other processes were subsequently suggested, among which treatment 

 of aniline with chloride or nitrate of mercury, with arsenic acid, and 

 many other substances may be mentioned. Magenta, often called 

 fuchsine, roseine, &c., soon became an article of large consumption. 

 A great impetus to this new branch of industry was given in France 

 by Messrs. Renard and Franc, who were the first to manufiicture the 

 new article on a commercial scale ; in this country, very soon after- 

 wards, Messrs. Simpson, Maule, and Nicholson engaged with great 

 spirit in the manufacture of this splendid dye, the production of which 

 has attained already colossal proportions. To Mr. E. C. Nicholson 

 more especially belongs the credit of hvaving developed this new in- 

 dustry to an unprecedented degree of perfection. 



Before proceeding, however, let me show you the formation of 

 Magenta by experiment. Among the many processes which I might 

 adopt for this purpose I select the action of corrosive sublimate upon 

 aniline, not because I consider this process superior to the others, — it 

 is, in fact, inferior to many, — but because it is, perhaps, the best 

 adapted for a lecture-experiment. This white powder is chloride of 

 mercury (corrosive sublimate) ; a small portion of this salt I mix in a 

 test-tube with perfectly colourless aniline. Let us stir the mixture 

 with a glass rod until it is converted into a perfectly homogeneous 

 liquid paste. This paste is still colourless ; but on gently heating it by 

 a gas-burner, it instantaneously assumes a splendid crimson of the 

 greatest intensity, a single drop of the liquid being capable of deeply 

 colouring a large beaker filled with alcohol. 



In all the processes which convert aniline into colouring matters, 

 a considerable number of secondary products are generated, which it is 

 rather difficult to separate from the principal product of the reaction. 

 These difficulties have been most perfectly overcome by Mr. Nicholson, 



