OP ARTS AND SCIENCES. 



91 



dissolving tlie substance with very little heat iu chloroform, and then 

 adding enough alcohol to start the separation of crystals ; in this way 

 a pure substance melting at 111° was obtained without diliiculty, which 

 was dried at about 70° and analyzed with the following results ; — 



I. 0.19G0 gr. of the substance gave on combustion 0.3012 gr. of car- 

 bonic dioxide and 0,0714 gr. of water. 

 II. 0.1926 gr. of the substance gave 1G.7 c.c of nitrogen at a tem- 

 perature of 23° and a pressure of 771 mm. 



Found 

 1. II. 



41.91 

 4.05 



Carbon 

 Hydrogen 



Nitrogen 



Calculated for 

 C8H(N02)3CH(C0,C2ll5),CN0s(C02C2Hr,)2. 



41.81 

 3.83 



9.76 



9.93 



The substance is therefore the mononitrite of trinitrophenylenedi- 

 malouic ester. 



Properties. — The substance crystallizes in rather thick plates with 

 parallel sides terminated at each end by two planes at an acute angle to 

 each other, these acute angles being usually, but not always, truncated 

 by planes at right angles to the parallel sides. The crystals are often 

 much twinned and grouped into very irregular forms. It has a lemon- 

 yellow color, and melts without decomposition at 111°. It is very 

 slightly soluble in boiling water, giving a pale yellow solution, essen- 

 tially insoluble in cold ; slightly soluble iu cold alcoliol, freely in hot ; 

 more soluble in methyl than in ethyl alcohol, whether cold or hot ; 

 both these solvents seem to produce a slight decomposition of the sub- 

 stance when heated with it ; very freely soluble in chloroform ; freely 

 soluble in benzol, or acetone ; soluble in ether, or glacial acetic acid ; 

 slightly soluble in carbonic disulphide ; insoluble in ligroine. The 

 best solvent for it is the mixture of chloroform and alcohol used as de- 

 scribed above. Strong sulphuric acid has no action on it in the cold, 

 but, when heated with it, dissolves some of it with a pale yellow color 

 after it melts; strong hydrochloric acid has no apparent action on it 

 either hot or cold ; strong nitric acid has no action on it in the cold, 

 but dissolves it slightly when hot, and if heated with it for two hours 

 and a half destroys it completely, tlie only product which we isolated 

 being oxalic acid ; on one occasion, however, another product melt- 

 ing near 1 10° was obtained in small quantity, but we did not feel 

 sufficiently interested in this part of the subject to prepare enough of it 

 to determine whether it was the dinitrite or a tartronic ester. One 

 thing, however, these experiments have established, namely, that the 



