OF ARTS AND SCIENCES. 303 



raise the carbon 2.58 per cent, an assumption improbable in itself, and 

 not supported by the appearance of the preparation, which had only a 

 slight dirty pink color. This we think is enough to condemn this 

 third explanation, but we add the following considerations, all of 

 which tell strongly in favor of the second, and against the third ex- 

 planation. (1.) Gabriel and R. Meyer* by the reduction of diui- 

 trophenylacetic acid with tin and hydrochloric acid obtained the 

 paramidooxindol direct, and it does not seem possible that our brom- 

 diamidophenylacetic acid, which differs from theirs only in containing 

 an atom of bromine, should be so much more stable. (2.) Our free 

 base agrees fairly well in properties with the paramidooxindol of 

 Gabriel and R. Meyer. Both are easily oxidized, soluble in hot water 

 or in alcohol, slightly soluble in benzol or carbonic disulphide, the only 

 difference being that our base is nearly insoluble in ether, whereas 

 theirs is soluble in it. The melting points also stand about where we 

 should expect, amidooxindol about 200°, our bromamidooxindol about 

 212°; in both cases there was so much blackening that the melting 

 point could not be accurately determined. (3.) Our base (or its chlo- 

 ride) gives the indol reaction, turning a piece of pine wood red if 

 boiled with it and dilute sulphuric acid, or if the wood, after being satu- 

 rated with a solution of the base, is soaked in strong hydrochloric acid. 

 This seems to us conclusive. The color is rather dull, and appears only 

 after some time ; but the objection which might be urged against this 

 argument on this account, that the bromdiamidophenylacetic acid was 

 converted into the bromamidooxindol by treatment with the acids, has 

 no weight, as in the preparation of the original chloride it was most 

 thoroughly exposed to the action of strong hydrochloric acid, both hot 

 and cold ; and yet this chloride, as we have shown by the analyses, 

 contained two atoms of hydrogen and one of oxygen more than is re- 

 quired by the chloride of the bromamidooxindol. 



These arguments seem to us to prove conclusively that the two 

 substances are bromamidooxindol C G H 2 BrNH 2 (CILCONH), and its 

 chloride C G H 2 BrNH,(CH 2 CONH)HCl.H 2 0, in spite of the fact that 

 we could not drive off the water of crystallization from the chloride 

 even at 135°. 



Properties of Bromamidooxindol, C G H 2 BrNH 2 (CH.,CONiI). 



As precipitated from its chloride it forms a heavy flocculent white 

 precipitate, which, when examined with the microscope, is seen to be 



* Ber. d. ch. G., xiv. 832. 



