MAUVE AND MAGENTA. 329 



except the illuminating gas — carburEtted hydrogen. The coal tar was, 

 it is true, collected and used ; hut it was regarded, from its disagreeable 

 smell, as a very unpleasant neighbour. The chemist has, however, taken 

 this coal tar, so offensive to our sense of smell, and he has extracted from 

 it several essences remarkable for their fragrance ; and again, from the same 

 black tar — to touch which was to be defiled — by a process of transmutation, 

 the chemist has evoked a colour which has carried joy to the hearts of the 

 Cardinals of Rome, and administered much pleasure to the Fashion rulers 

 of our own and other lands. 



Aniline, we have said, is one of the products obtained from coal tar. 

 This substance derives its name from Anil, the name of one of the plants 

 producing Indigo, as from: this colouring matter Aniline was first separated. 

 From Indigo-blue this Aniline can be obtained by treating it with potash, 

 and then distilling the mass ; but Hofmann discovered a far more abundant 

 source of it in the oil of gas tar. It would be tedious, and after all not 

 very intelligible, to describe the processes, but the result of many careful 

 distillations is a brown oil ; this, by purification, becomes a colourless 

 liquid, possessing a peculiar aromatic odour. This is the important Aniline, 

 a chemical compound, consisting of twelve proportions of carbon, seven of 

 hydrogen, and one of nitrogen. 



This interesting substance combines with acids to form crystalline salts ; 

 its combination with oil of vitriol (sulphuric acid) forms sulphate of Aniline, 

 which is the most important. These crystals, which are beautiful colour- 

 less plates of a silvery lustre, become red by exposure to the air ; and here 

 is developed the secret of its producing the exquisite reds and purples of 

 which we write. 



By adding oxygen to, that is, by oxidising this salt of Aniline, the red 

 or purple colour is obtained ; and as we vary the agent imparting the oxygen, 

 so we have the means of varying the dye, and may secure any of the shades, 

 between the blues and the reds, which are met with in the shops. 



As we have stated, Mr Perkins was the discoverer of the original Mauve. 

 He was a student of Dr Hofmann's, and employed by that chemist to assist 

 him in his investigations of the products from coal. The preparation of 

 Aniline was described by Dr Hofmann, and he first showed that its pre- 

 sence could be detected by the violet colour it gave when treated with 

 chlorine. This was the key to everything that has since been done, and it 

 is not a little curious to see how the changes have been rung by the chemists 

 on oxidising agents. A few examples will suffice : 

 Salt of Aniline, with Bichromate of Potash ...Mauve, and Perkins' Purple. 



Ditto Bichloride of Mercury ...Magenta, and other Beds. 



Ditto Bibromide of Tin Fuchsiacine, &c. 



Ditto Nitric Acid Azaleine, Solferina, &c. 



Ditto Arsenic Acid Reds and Purples. 



Ditto Peroxide of Lead Roseine. 



Ditto Manganese Salts Pink, Red, and Purple, Sol- 



ferina, &c, 



