62 ELECTROLYSIS AND ELECTROS 'YN THESIS 



Hydroquinone in an aqueous solution acidified with 

 sulphuric acid could be quantitatively converted into 

 quinone at the anode: 



2C.H 4 (OH) a + O = H,0 + C 6 H 4 (OH) a .C,H 4 0, 



The same compound was also formed when alter- 

 nating currents were used. 



Voigt, 1 by the electrolytic oxidation of suitable 

 mixtures of bases, prepared rosaniline, chrysaniline, 

 safranine, and p-leucaniline. His object in these 

 researches was the same as that of Goppelsroeder; 

 namely, the preparation of the important dyes of the 

 aniline series. 



If electrolytic oxygen is permitted to act upon 

 aniline, dissolved in concentrated acetic acid solution, 

 acetanilide is formed; by using a dilute solution, 

 however, amido-hydroquinone is obtained. 



So far as can be learned from the literature these 

 investigations have not been concluded, which is also 

 the case with those of Poising, 8 who by the oxidation 

 of p-phenylene-diamine obtained a beautiful blue dye 

 similar to indigo. 



Poising obtained p-phenylene-diamine by the elec- 

 trolytic reduction of amido-azo-benzene. 



From the electrolysis of benzene -p-phenylene-diamine 



1 Ztschr. f. angew. Chem., 1894, p. 107. 

 1 Ztschr. f. Elektrochemie, 2, 30. 



