Dr. Hofmann on the Metamorphoses of Indigo. 607 



confirmed by experiment. Bromisatine has been as yet but 

 little studied. Erdmann* obtained it in very small quantities 

 by the direct action of bromine on indigo. Laurent did not 

 prepare this subtance ; by the action of bromine on isatine he 

 obtained immediately dibromisatine (bromisatinese). The first 

 compound can however easily be formed by employing a 

 solution of bromine in water instead of anhydrous bromine. 

 In two experiments I obtained bromisatine alone, as is shown 

 by the following analysis. The compound is dissolved out 

 by boiling spirits of wine, washed with water to remove all 

 trace of hydrobromic acid, and recrystallized in boiling alco- 

 hol, from which it separates in shining prisms. 



The following result was obtained on combustion with 

 chromate of lead; — 



I. 0'3270 grm. of bromisatine gave 0*5090 grm. of carbonic 

 acid and 0*0625 grm. of water. 



II. 0*3955 grm. of bromisatine gave 0'6165 grm. of car- 

 bonic acid and 0*0750 grm. of water. 



These numbers give the following per-centages, which are 

 placed in apposition with the calculated quantities : — 



Theory. Experiment. 



16 equiv. Carbon 



4 ... Hydrogen 



1 ... Bromine . 



1 ... Nitrogen . 



4 ... Oxygen . 



1 ... Bromisatine= 2805-35 

 The properties of this body, which I obtained in large quan- 

 tities, agree completely with those of chlorisatine, to which 

 on this account I refer in the memoirs of Erdmann and Lau- 

 rent. 



On submitting bromisatine to distillation with fused hydrate 

 of potash, exactly the same phenomena are observed as those 

 I have already described in the same process with chlorisa- 

 tine, and there distils over a new base containing bromine. 



E. Bromaniline [Amabropheiiese). 

 a. Composition. 



The purification of the crude product of distillation is made 

 with the same ease as in the case of the corresponding chlo- 

 rine compound. The analogy in the mode of formation of 

 the two left no uncertainty as to the composition of bromani- 

 * Journal fUr Prakt. Chem., Bd. xix. S. 358. 



