OP ARTS AND SCIENCES. 2G7 



these longer prisms, and we could not decide whether these latter 

 were a different substance or merely a different habit of the same. 

 Second. When the crystals were treated with sodic hydrate and alco- 

 hol a little of a soluble red salt was formed around each crystal, but 

 we could not convert the whole of the crystals into this salt. This 

 seemed to point to the presence of an impurity, from which the salt 

 was formed. Third. We found almost at the very end of the term, 

 that by warming the bromtrinitrophenylmalonic ester with strong ni- 

 tric acid for three hours, instead of a few minutes, a red substance was 

 obtained, which crystallized from alcohol, became white, and melted 

 at 156° instead of 125°, and, what was as distinctive as the different 

 melting point, fused to a colorless liquid, and gave a red solution with 

 aqueous sodic hydrate. This substance was discovered so late that 

 we had no time to investigate it, but some of it seemed to be formed 

 even on shorter heating (15 minutes) with the nitric acid. For these 

 reasons, we have decided that it is wiser to postpone the publication 

 of our analyses of the substance melting at 125° until the work has 

 been repeated with samples in regard to the purity of which there 

 can be no doubt. We add such results of our work as are established 

 with certainty. The analyses made by us showed that there were 

 three atoms of nitrogen to one of bromine in the substance, and there- 

 fore the action of the nitric acid did not consist in the introduction 

 of another nitro, or nitroso group. The fact that it is insoluble in 

 aqueous sodic hydrate shows that it is not a free acid, and its action 

 with hydrochloric acid would indicate that it was an ester, as, when 

 heated to 135°-140° with this acid in a sealed tube for 36 hours, a 

 gas was given off burning with a green-bordered flame, and giving a 

 white precipitate with lime-water, which therefore must have contained 

 ethyl chloride and carbonic dioxide. The solid product of this action 

 was partly viscous and partly crystalline ; the latter melted in the 

 crude state above 180°. It has been stated already that the substance 

 melting at 125° turns red aud increases in volume when it melts; this 

 change, which takes place to a limited extent even when it is kept at 

 100° for some time, is accompanied by loss of weight, as a sample 

 kept at its melting point for some days lost at least 17 per cent, and 

 gave a residue consisting of two or more substances, one white and 

 crystalline, the other red and viscous. 



