220 fossil hydro-carbons — 



Colour. 



The production of colour from coal-tar bases, is a branch of the great hydro- 

 carbon industry still in its infancy : Yet so encouraging are present practical 

 results that it is hardly predicting too much to say that eventually we shall 

 be supplied with every requisite dye from the same source, and if the 

 brilliant, though limited, number of colours of coal-tar origin, at present 

 existing, are a fair sample of what is to follow, I feel sure the public will 

 very readily bid a lasting farewell to most of the dyes obtained from plants 

 and animals. 



Amongst the various residuary products of the coal-gas manufacture 

 already enumerated, and which are mainly included in coal-tar, is a basic 

 oil termed " aniline " from " anil" the Hindostanee for indigo, and from 

 which dye it was formerly obtained, although only in small quantities, and 

 for purely chemical and experimental purposes. The quantity of aniline 

 existing as a distinct and separate body in coal-tar, is, however, extremely 

 email, and this invaluable source of so many shades of colour is now 

 obtained from Benzole, another ingredient in the bundle of hydro-carbon 

 treasures, just now exciting so much attention. Of coal-tar naphtha about 

 25 per cent., or one quarter part, is benzole, which, on being dissolved in 

 nitric acid, yields the well-known product nitro-benzole, presently to be 

 noticed as an artificial oil of almonds. From nitro-benzole, aniline is now 

 produced in large quantities, and of the numerous processes by which that 

 result can be obtained, Mr. Perkins stated in his admirable paper read 

 before the Chemical Society, that Bechamp's plan was the one most 

 generally adopted, by which the nitro-benzole is submitted to the action 

 of acetate of lime, the product being aniline. 



From aniline, many colours have already been elaborated ; but as I 

 have not space sufficient to describe at length the chemical treatment of 

 this basic oil in their production, I will simply mention the principal coal- 

 tar dyes, that the reader may be enabled to identify the source whence they 

 are obtained. 



" Mauve" is as familiar to us as a household word, and the remembrance of 

 its introduction into the gay world will be long retained ; for it came to the 

 lescue at a time when the connoisseurs of colour were positively languishing 

 for something novel wherewith to attract the votaries of fashion, and 

 enjoyed no ordinary measure of success and popularity. The name is 

 derived from the terminal syllable of the French for the mallow giiimauve, 

 to the flower of which plant this new colour bears a striking resemblance. 

 Aniline purple, phenamine, indisine, &c, are synonyms of this same dye. . 

 Violine and roseine are other shades of purple, thought by Mr. Perkins, 

 who is a chief authority in such matters, to be closely allied to the mauve, 

 and the names indicate a resemblance more or less complete to the tints of 

 the violet and rose. 



Magenta is another dye product of aniline, and equally popular with the 

 mauve. Its association with the blood-stained field of Italy betrays its 

 resemblance to some gory tint, sad and sorrowful to mortal eye. It is, 



