OP ARTS AND SCIENCES. 259 



allowed to stand 40 to 60 hours in a corked flask at ordinary tem- 

 peratures. As soon as the sodium malonic ester was added, the 

 liquid became dark blood-red, and on standing this color gradually 

 increased in intensity, while at the same time a precipitate of sodic 

 bromide was thrown down. The product of the reaction was mixed 

 with about three quarters of a litre of water, and acidified with dilute 

 sulphuric acid,* which decomposed the red salt, setting free the ester. 

 Ether was then added, and, after shaking thoroughly, the ethereal and 

 benzol solution separated from the aqueous liquid, which was ex- 

 tracted once more with ether. On distilling off the ether and benzol 

 from the extract, a dark oily residue was left, which was mixed with 

 a little alcohol, when, upon stirring, it solidified to a mass of prismatic 

 crystals. These were sucked out on the pump, washed with a little 

 cold alcohol to remove the adhering oil, and purified by crystallization 

 from hot alcohol, till they showed the constant melting point 104°- 

 105°. The oil which was sucked out from the crystals, or removed 

 from them by alcohol, upon standing, deposited an additional amount 

 of the substance, which was purified in the same way as the main 

 portion. The substance, after being dried in vacuo, was analyzed 

 with the following results : — 



I. 0.2235 gr. of the substance gave on combustion 0.28G0 gr. of 

 carbonic dioxide, and 0.0629 gr. of water. 

 II. 0.1930 gr. of the substance gave 16.2 c.c. of nitrogen at a tem- 

 perature of 21°, and under a pressure of 775.9 mm. 



III. 0.2548 gr. gave 20.1 c.c. of nitrogen at 18°.5, and 784 mm. 



pressure. 



IV. 0.2080 gr. gave by the method of Carius 0.0870 gr. of argentic 



bromide. 

 V. 0.2512 gr. gave 0.1034 gr. of argentic bromide. 



Calculated for Found. 



C fi HBr(N0 2 ) 3 CH(C00C 2 H 5 ) 2 . I. II. III. IV. V. 



Carbon 34.67 34.89 



Hydrogen 2.67 3.13 



Nitrogen 9.33 9.75 9.38 



Bromine 17.78 17.80 17.52 



The yield was good, when compared to that obtained in similar 

 preparations from other substances ; the best result was as follows : 



* Dilute nitric acid, which was used in some of the earlier preparations, 

 seemed to diminish the yield. 



