358 MM. Martius and Griess on Alizarine. 



qs H 3 I 3 0. The crude product of the action of the protochloride, 

 treated with soda, is precipitated by dilute sulphuric acid ; this 

 precipitate is exhausted by weak alcohol at the boiling-point, 

 which dissolves out the biniodized phenylic acid, G 3 H 4 I 2 0, 

 and the residue is then crystallized from strong boiling alcohol. 

 The crystals are yellow, easily soluble in ether, and decompose, 

 when heated, with disengagement of much iodine. 



In the hope of getting a more highly iodized compound, the 

 author acted with protochloride of iodiue on teriodized phenylic 

 acid. Under these conditions all the iodine became free, and 

 quintichlorophenic acid, G 6 HC1 5 0, was obtained, subliming in 

 magnificent white needles 3 to 4 centimetres in length. 



Seekamp* found that when a solution of oxalic acid containing 

 some uranium-salt was exposed to the sun's rays it was decom- 

 posed into carbonic acid, carbonic oxide, and formic acid. 



Succinic and pyrotartaric acids, which are homologous with 

 oxalic acid, experience an analogous decomposition under the 

 same circumstances. A 5 per cent, solution of succinic acid, to 

 which 1 per cent, of uranium- salt was added, exposed to the 

 sun's rays soon became green ; succinate of uranium was depo- 

 sited as a green powder, carbonic acid was given off, and the 

 completely decolorized liquid furnished propionic aeid. Pyro- 

 tartaric acid in like manner was decomposed with formation of 

 butyric acid. The decompositions which take place are as 

 follows : — 



C 4 H 6 4 = G0 2 + G 3 H 6 2 



Succinic acid. Propionic acid. 



C 5 H 8 4 -= GO 2 + G 4 H 8 G 2 . 

 Pyrotartaric acid. Butyric acid. 



Chloroxynaphthalic acid, G 10 H 5 CIO 3 , differs from alizarine, 

 G 10 H 6 O 3 , in containing an atom of chlorine in the place of hy- 

 drogen ; and many years ago Wolff and Strecker endeavoured, 

 but without success, to replace the chlorine in the above com- 

 pound by hydrogen, and thus produce alizarine from naphthaline. 



Martius and Griess + have succeeded in producing from naph- 

 thaline a body of the same composition as alizarine, but entirely 

 different in properties. The starting-point for their investiga- 

 tion was binitronaphthylic alcohol, G 10 H 6 (NO 2 ) 2 0, a substance 

 recently introduced into manufactures, and a description of which 

 is promised. When this body is acted upon by tin and hydro- 

 chloric acid, as a direct product of the action a beautiful tin 

 double salt of a new base is produced, 



G 10 H 6 (NH 2 ) 2 0, HC1 Sn 2 CI 2 . 

 * Liebig's Annalen, February 1865. f Ibid. June 1865. 



