OF ARTS AND SCIENCES. 



95 



alcohol crystals were obtained which showed the characteristic rhombic 

 form of the uitrite of broradinitrophenylmalouic ester. This experi- 

 ment therefore seemed to show that the action of heat consisted only 

 in the complete decomposition of a portion of the nitrite of bromdini- 

 trophenylmalonic ester, and, as it did not promise to give the desired 

 tartronic ester, further work in this direction was abandoned. 



Reduction of the Nitrite of Bromdinitrophenylmalonic Ester. 



The conversion of the nitrite of broratrinitrophenylmalonic ester into 

 the corresponding tartronic ester by nitric acid, or by the action of 

 heat, indicates that the group NO2 in the side-chain is attached to 

 the molecule by oxygen instead of nitrogen, or, in other words, that 

 the substance is a nitrite, and not a nitro compound ; but, as we could 

 not consider this a conclusive proof of the oxygen attachment, we 

 have studied the reduction of a body of this class, selecting for this 

 purpose the dinitro compound, because it is more easily prepared than 

 the corresponding substance containing three nitro groups, and also 

 because the product obtained from it by reduction would probably be 

 more stable than one containing one more amido group. 



Six grams of the nitrite of bromdinitrophenylmalonic ester divided 

 into three lots of two grams each were mixed with granulated tin, 

 strong hydrochloric acid, and a few drops of alcohol, and after adding 

 a piece of platinum to accelerate the reaction, were allowed to stand 

 on a steam radiator (50°-7U°) until all the organic matter had dis- 

 solved, and no further action was observed, which happened usually in 

 about an hour and a half. If quantities larger than two grams were 

 used a very dark colored solution was obtained. The solution poured 

 off from the excess of tin was freed from stannous and stannic chlorides 

 by means of sulphuretted hydrogen, when a residue was obtained by 

 evaporation of the filtrate, which gave off ammonia gas when treated 

 with an alkaline hydrate, and formed a precipitate of ammonic chlor- 

 platinate with chlorplatinic acid ; it evidently therefore contained am- 

 monic chloride in addition to the chloride of the organic base. The 

 washings of the suljihide of tin, which were worked up separately 

 from the filtrate, on the other hand, yielded crystals which showed only 

 a very slight amount of ammonic chloride by the same tests, and ac- 

 cordingly these crystals were dried at 100°, and analyzed with the 

 following results : — 



I. 0.1980 gr. of the substance gave 25.25 c. c. of nitrogen at a tem- 

 perature of 23° and a pressure of 764.8 mm. 



