OP ARTS AND SCIENCES. 107 



solvents that a crystallization of them in any quantity was a matter of 

 very great difficulty. In spite of the great difference in their appear- 

 ance they both had the same composition, that of the expected triami- 

 dodinitrobenzol, as is shown by the following analytical data, in which 

 Analyses I. and II. were made with the reddish yellow needles, Anal- 

 ysis III. with the black amorphous body. 



I. 0.3000 grm. of the substance crystallized in yellow needles gave 

 on combustion 0.3710 grm. of carbonic dioxide and 0.1 085 grm. 

 of water. 

 II. 0.1510 grm. of the crystalline substance like that used in I. gave 

 42.4 c.c. of nitrogen at a temperature of 8°. 6 and a pressure of 

 748.5 mm. 

 III. 0.3028 gi - m. of the substance deposited in black amorphous masses 

 gave on combustion 0.3778 grm. of carbonic dioxide and 0.0925 

 grm. of water. 



Properties. — The triamidodinitrobenzol, as deposited by the action 

 of alcoholic ammonia on tribromdiuitrobenzol, forms either reddish 

 yellow needles, or nearly black amorphous masses. When the sub- 

 stance is crystallized from a mixture of chloroform and alcohol, which 

 can be done only wdth great difficulty on account of its slight solubility. 

 it forms microscopic yellow plates, or broad flattened prisms, and, if 

 the treatment with the mixed solvents is carried on in a continuous 

 extracter, these crystals collect into characteristic yellow masses shaped 

 like an S or U. It does not melt even above 300°, but is decomposed 

 if heated more intensely. It is very slightly soluble in alcohol or 

 chloroform, although it imparts a perceptible yellow color to these boI- 

 vents, more soluble in nitrobcnzol, but cannot be obtained in crystals 

 easily from this solution, so that a mixture of alcohol and chloroform 

 is the best solvent for it. In the other common solvents it is either 

 entirely insoluble or very slightly soluble. In this respect it reseml 

 the corresponding trinitro compound, but it is, if there is any dill', rence, 

 slightly more soluble than that. The substance does not form definite 

 salts, although it dissolves easily in concentrated hydrochloric acid 

 forming a dark red liquid. It shows therefore a greater tendency to 



