172 



Mr. P. Griess on some 



[Feb. 15, 



crystallizes in white scales, rather insoluble in hot water and extremely so 

 in cold. Curiously enough, it does not possess the property of combining 

 with acids, but with bases it forms salts having the general formula 

 C 8 H 8 N 3 3 , M'. Its silver salt is a white crystalline precipitate. This new 

 amido-acid is remarkable for its instability ; boiled with hydrochloric acid 

 or with baryta-water, it is decomposed in the following manner : — 



QjH.N^ = C.H N.O, + NH^. 



/3 amidoura- New acid. Ammonia, 



midobenzoic 

 acid. 



The new acid, C 8 H 6 N 2 3 , thus obtained forms small white nodules, 

 which are insoluble in all ordinary neutral solvents. It combines with am- 

 monia, forming a salt which crystallizes in difficultly soluble long needles. 

 Its hot ammoniacal solution, when mixed with barium chloride, solidifies 

 to a pulp of white needles, which, when dried between filter-paper, have 

 the composition (C 8 H 5 N 2 3 ) 2 , Ba + 4H 2 0. With respect to its consti- 

 tution, I am inclined to regard it as amidobenzoic acid, in which one atom 

 of hydrogen is replaced by the group [(CO)N] : 



C 8 H 6 N 2 3 = C 7 H 4 (NH 2 ) [((CO)N)]0„ 



and therefore propose to call it (3 amidocarboxamidobenzoic acid. 



y nitrouramidobenzoic acid, when treated with tin and hydrochloric acid, 

 behaves differently from either of the other isomeric acids, not yielding an 

 amido-acid, but suffering at once a much deeper decomposition, as repre- 

 sented in the following equation : — 



C.H,^ + H, = (VH.N^O, + NH, + H^O. 



y nitrouramido- New acid. Ammonia. Water, 



benzoic acid. 



This new acid, C 8 H 6 N 2 3 , which has the same composition as the /3 

 amidocarboxamidobenzoic acid just described, is not identical but only iso- 

 meric with it, and I shall therefore designate it by the name of y amido- 

 carboxamidobenzoic acid. It crystallizes in white needles, which are almost 

 insoluble in water, alcohol, and ether. 



Action of strong Nitric Acid on the Isomeric Nitrouramidobenzoic 



Acids. 



In the earlier part of this notice it was stated that three isomeric dinitro- 

 uramidobenzoic acids were produced by the action of strong nitric acid on 

 uramidobenzoic acid, but that their separation could not be conveniently 

 effected, owing to the great resemblance in their properties. Any of these 

 isomeric dinitro-acids, however, may be obtained in a pure state by dis- 

 solving the corresponding nitrouramidobenzoic acid in fuming nitric acid, 

 free from nitrous acid. On diluting the solution with water, the dinitro- 



