208 PROCEEDINGS OP THE AMERICAN ACADEMY 



The silver salt precipitated from the solution of the ammonium 

 salt by the addition of nitrate of silver, is obtained in the form of 

 small, white laminae, which are tolerably insoluble in water, and 

 gradually assume a brown color on exposure to the sunlight. The 

 analysis of this salt coincided closely with the formula 



/ ' '\COOAff 

 SO., 



Xntr/ 



an 



COOAff 



o 



6'-^3 



xnh^ 



Calculated. Found. 



Ag= 37.45 37.62 



The barium salt is extremely soluble, and not adapted for analysis. 



The reaction of para-amido-benzoic acid, just described, recalls the 

 analogous reaction of phenol with sulphuric acid. Glutzt* and 

 Annaheim t have shown that, if an excess of sulphuric acid I )e avoided, 

 oxysulpho-benzide is obtained with great ease. As in the case of 

 oxysulpho-betizide and all members of the snlphine group, our com- 

 pound should also pass over into the corresponding sulphonic acid, 

 by increasing the amount of sulphuric acid used. 



Unfortunately we are compelled temporarily to interrupt the in- 

 vestigation, but hope at an early date to be able to communicate 

 farther experiments in the direction mentioned. 



Merz and Weith J obtained several years since a dicarboxyl-sulph- 



carbauilid, 



/NHQirCOOH 



XNnCgii^cooii 



a well-defined crystalline compound, by the action of carbon disul- 

 phide on metamido-benzoic acid. We have sought to prepare the 

 corresponding derivative of para-amido-benzoic acid, but so far without 

 success. The alcoholic solution of carbon disulphide and para-amido- 

 benzoic acid was heated in an open flask and in sealed tubes at various 

 temperatures. In all cases we obtained a yellow, resinous mass, from 

 which no well-characterized compound could be separated. 



Berlin, Univeksitats-Laboratorium, April, 1877. 



* Ann. Chem. Pharm., 147, 52. t Ann. Chera. Pharm., 172, 28. 



t Ber. Deutsch. Chem. Gesell., 3, 812. 



