302 PROCEEDINGS OF THE AMERICAN ACADEMY 



If the first of these explanations is the true one, the chloride made 

 by adding hydrochloric acid to the free base would be the chloride 

 of the bromamidooxindol, and therefore different from the original 

 chloride of the bromdiamidophenylacetic acid. To settle this point, 

 we set free the base with ammouic hydrate from a quantity of the 

 original chloride, and, after washing until free from ammonic chloride, 

 dissolved it in dilute hydrochloric acid and crystallized it from the 

 slightly acid solution. The general habit of the crystals of the two 

 chlorides (the original one and that made from the free base) was the 

 same, but there were differences in the modifications on the ends of 

 the prisms which made the identity of the two somewhat doubtful ; 

 we accordingly analyzed the chloride made from the free base, with 

 the following results : — 



0.1853 gr. of the substance gave on combustion 0.2328 gr. of car- 

 bonic dioxide and 0.0678 gr. of water. 



Calculated for Calculated for Found. Analyses of 



CgHjBrNoOIICl. CjHaBrNjOjHCl. Original Chloride. 



Carbon 36.43 34.12 34.26 34.17 33.93 



Hydrogen 3.04 3.55 4.06 4.93 4.03 



There can be no doubt, therefore, of the identity of the two chlo- 

 rides, and the first explanation must be abandoned. 



The second explanation requires that the chloride should contain 

 one molecule of water of crystallization. This point was tested by 

 heating the chloride with the following result: — 



0.2517 gr. of the chloride heated for 6 hours at first at 110°, later 

 to 135°, lost 0.0024 gr. 



Calculated for 

 CsHiBrNoOHClHjO. Found. 



Water 6.42 0.95 



From this it appears that, if the chloride contains water of crystalli- 

 zation, it does not lose it at 135°. The slight loss of only 2.4 mgrs. 

 could be sufficiently accounted for by the decomposition of the salt, 

 which had turned dark gray on the surface, and for this reason too the 

 heating could not be repeated at a higher temperature. 



This result, unfavorable to the second explanation, necessitates the 

 discussion of the third, — that the free base is bromdiamidophenylacetic 

 acid, — which otherwise we should not have thought worthy of consid- 

 eration. As has been already stated, the analyses of the free base do 

 not agree with this explanation, and in order to adopt it we must 

 assume that the substance had undergone a decomposition sufficient to 



