149 



becomes attached to nitrogen without being influenced by the relative weights 

 of the entering groups. The hope that the introduction of radicals of nearly 

 the same weight (CeHsCO — 105, CsHuCOO — 115) would result in the forma- 

 tion of isomeric substances was not realized, the velocity of the rearrange- 

 ment being almost instantaneous in every case. Consequently the mechan- 

 ism of the rearrangement cannot be cxj^lained. It is possible that there is 

 an equilibrium of the two isomeric forms and that one of them is in large ex- 

 cess, but there is little evidence to support this view. Work already begun 

 with the orthoaminomercaptans may throw light upon the problem. 



