OP ARTS AND SCIENCES. 



81 



nitrite of the corresponding malouic ester, but this method has no ad- 

 vantage over the preparation direct from the malonic ester described 

 above, except in the case of the nitric acid mother liquors from mak- 

 ing the nitrite, which yield on longer heating with nitric acid a small 

 amount of the tartronic ester, and this is worth saving on account of 

 the tedious and costly preparation of the mother substance. 



The substance dried in vacuo was analyzed with the following 

 results : — 



I. O0I95I gr. of the substance gave on combustion 0.2380 gr. of 

 carbonic dioxide and 0.0584 gr. of water. 

 II. 0.2049 gr. of the substance gave 16.2 c. c. of nitrogen at a tem- 

 perature of 17°. 5 and a pressure of 763.7 mm. 



III. 0.2044 gr. of the substance gave according to the method of 



Carius 0.0836 gr. of argentic bromide. 



IV. 0.2272 gr. of the substance gave 0.0930 gr. of argentic bromide. 



IV. 



17.42 



Our reasons for considering this a tartronic ester rather than a 

 phenol have been given already in the introduction to this paper. The 

 yield is satisfactory, considering the amount of loss to be expected 

 from such a method of preparation ; 1 gr. of bromtrinitrophenylmalonic 

 ester gave 0.4 gr. of the substance, or about 40 per cent of the theo- 

 retical yield. 



Properties. — The bromtrinitrophenyltartronic ester crystallizes from 

 alcohol in long white prisms, terminated by planes at a very obtuse 

 angle to each other, so that the ends look almost but not quite square. 

 These crystals are often arranged in radiating groups, and in that case 

 are generally much more slender than when occurring in isolated prisms. 

 It is deposited from its solution in hot nitric acid in rather sharp slen- 

 der needles. It melts at 156°, and is nearly but not quite insoluble 

 in water, whether hot or cold ; soluble in cold alcohol, freely in hot ; 

 rather more soluble in methyl than in ethyl alcohol ; freely soluble 

 in benzol, glacial acetic acid, or acetone; soluble in ether, and some- 

 what more so in chloroform ; nearly insoluble in carbonic disulphide; 

 insoluble in ligroine. The best solvent for it is hot alcohol. Strong 

 sulphuric acid has no action upon it in the cold, but if hot, dissolves 



VOL. XXVI. (N. 8. XVIII.) 6 



