Dr. Hofmann oti the Metamorphoses of Indigo. 505 



was distilled off. The red crystals were separated by filtra- 

 tion, washed and crystallized from hot alcohol. 



The prismatic crystals thus obtained produced on burning 

 with chromate of lead the following result: — 



0*2955 grm. gave 0-5697 grm. of carbonic acid and 0*0695 

 grm. of water; corresponding in the 100 pans to 



Carbon . . . 52-57 



Hydrogen . . 2*61 

 This substance was consequently nothing but pure undecom- 

 posed chlorisatine, which contains in 100 parts — 



Carbon . . . 52-88 



Hydrogen . . 2-25 



This compound, Cjg < CI > NO4, would have contained 

 LBrJ 

 Carbon . . . 36-90 

 Hydrogen . . 1-15 

 The small quantity of hydrobromic acid observed in this ac- 

 tion of bromine on chlorisatine may have arisen from a small 

 admixture of isatine, which would be converted into bromisa- 

 tine. By continued action of bromine in sunshine, perhaps 

 another result might be obtained. 



D. Chlorodibromaiiiline {Amachlohrophenose). Cjg ^ CI > N. 



LBrJ 



It has been already stated that aniline is decomposed with 

 facility by bromine. On adding bromine water to the solu- 

 tion of a salt of chloraniline, a white precipitate takes place, 

 which dissolves in boiling alcohol, producing a slight violet 

 colour, and crystallizes on cooling in needles. The same 

 compound can be obtained by the direct action of bromine on 

 chloraniline. On adding bromine to the crystals of the latter, 

 a very violent reaction lakes place, with great elevation of 

 temperature and evolution of hydrobromic acid, the mixture 

 at the same time assuming a violet colour. Bromine is to be 

 added till the mass on being fused no longer absorbs any 

 more. The crystalline product is then to be allowed to cool, 

 and well-washed till all trace of hydrobromic acid is removed. 

 By recrystallization from alcohol, white crystals are obtained, 

 which have generally a shade of red. 



Fritzsche, as is known, has discovered that by the action of 



bromine on aniline there is formed a body, C,2 -s t> f ^ N, 



which he called bromaniloid. From this decomposition we 

 can already foresee the composition of the product which I 

 obtained by the action of bromine on the chlorinated base. 



