506 Dr. Hofmann on the Metamorphoses of 'Indigo. 



This must stand in the same relation to the bromaniloid that 

 the chlorinated base does to aniline, and consequently would 



be expressed by the formula C12 -^ CI >-N. 



LBrJ 

 This conclusion is completely confirmed by the analysis. 



The combustion with chromate ot lead gave the following 

 results : — 



0'520 grm. crystals, dried at the temperature of the air, gave 

 0*4<85 grm. of carbonic acid and 0"070 grm. of water; cor- 

 responding in the 100 parts to 



Carbon . . . 25-4S 

 Hydrogen . . 1'52 

 which will give the calculated composition, — 



Theory. Experiment. 



12 equiv. Carbon . . . = 900-00 25-52 25-43 

 4 ... Hydrogen . . = 50-00 1-41 1*52 



1 ... Chlorine . . . = 44-2-65 



2 ... Bromine . . . =1956*61 

 1 ... Nitrogen . . . = 177-04 

 1 ... Chlorodibromaniline = 3526-30 



The formula of this compound is C,2 -s n^ r N, and it 



contains Carbon = 22* 15 



Hydrogen = 1-22 

 This body is completely insoluble in water, but soluble in al- 

 cohol and aether. It melts under water into a brown oily 

 fluid, which can be distilled over with the vapour of water; it 

 crystallizes in shining needles on the sides of the receiver. 

 Chlorodibromaniline, like the trichloraniline, no longer pos- 

 sesses basic properties. It is soluble in boiling hydrochloric 

 acid, out of which however the greater part again recrystallizes 

 unchanged on cooling. The portion soluble in hydrochloric 

 acid at the ordinary temperature is precipitated by the addi- 

 tion of water. Strong sulphuric acid likewise forms with it a 

 solution of a violet colour, from which it is also precipitated 

 by the addition of water. Neither potash nor ammonia decom- 

 poses this substance, which by heat is slightly soluble in these 

 fluids without the least change. It does not combine with bi- 

 chloride of platinum or mercury, or with oxide of lead. Con- 

 centrated nitric acid decomposes the chlorodibromaniline. 



Action of fused Hydrate of Potash on Bromisatine. 



It was evidently to be expected that the brominated isatine 

 would yield the same results as the chlorisatine. This was 



