OXIDATTO.V PRODUCTS OF DIANISIDINE. 169 



allowed to stand for a week in jiresence of acid, and is probably 

 a demethylated derivative of the diimine: the black precipitate 

 formed is the almost insoluble hydrochloride of the demethylated 

 compound, and only g'ives the blue coloration on dilution and 

 heating. Another bye product is obtained on boiling- the quiu- 

 hydronic salts with acid water for some time : a black slimy pre- 

 cipitate is g'ot which gives only a dirty olive coloration with sul- 

 l')huric acid, and was therefore not investigated. 



Following W'illstaetter, I attennpted to make the true 

 quinonediimine from dianisidine in chloroform with lead dioxide. 

 The product was mainly the brown base CosHagO^N^ (m.p. 

 220-225°), along with a small quantity of a higher polymer, very 

 sparingly soluble in all solvents, of chocolate colour, and giving 

 a pure blue coloration to sulphuric acid (m.p. 245^). From the 

 analogy of Bandrowski's work on polymerisation of c[uinone- 

 diimine to CisHjcN,,,''' this sparinglv soluble 'substance is probablv 

 C,,H,.,0„N^, vis^:: 



MeO NH., NH., OMe 



<_> " < 



MeO 



Organic Cliemistry is nowadays so specialised that there is 

 nothing left in it of interest from the mental point of view — ex- 

 cept filling up cracks in the plaster of the edifice. For example, the 

 new substance I describe is about the 120th known isomer of the 

 formula Ci^Hj^OoNg, so I cannot imagine anyone taking a real 

 interest in investigating ordinary colourless substances under 

 circumstances such as these. It is the great intrinsic beauty of 

 the substances which I describe, and the interesting problem of 

 the cause of the multiplex colour-Changes which alone attract 

 me to work at this field, despite the manifest special difficulties 

 of doing organic work in South Africa without satisfactory 

 appliances. 



DelavaN'S C0MET.--A new comet, 191.3/, was dis- 

 covered at La Plata by M. Delavan on December 17th, ten months 

 before perihelion, which will be reached on October 4th. The 

 comet will probably be a grand naked-eye object, for even 

 Halley's comet was not discovered until eight months before 

 perihelion, and was then only of the i6th magnitude, whereas 

 that of Delavan's at discovery was loj. On March 29th it will 

 be nearX Ceti, vh., 2h. 56m. R.A. andS" 55' N.D. 



* Ber. 1894. p. 480. 



