290 PROCEEDINGS OF THE AMERICAN ACADEMY 



acetone and potassic hydrate on dinitro compounds of the aromatic 

 series. 



In our first experiment with acetic ester we used the commercial 

 article without specially drying it. The action was carried on in 

 the usual way, 5 gr. of trihromtrinitrohenzol heing used. The 

 aqueous washings gave tests for nitrite and bromide, hut the organic 

 product was found to consist principally of the tribromdinitro- 

 phenetol melting at 147°, described in our previous paper.* For 

 greater certainty it was analyzed, with the following results : — 



I. 0.2972 gr. of the substance gave by the method of Carius 

 0.3721 gr. of argentic bromide. 

 II. 0.2788 gr. of the substance gave 0.3535 gr. of argentic 

 bromide. 



This experiment called our attention to a subject which we had 

 already studied without any very definite result, that is, the condi- 

 tions under which the phenetol C 6 Br3(N0 2 ) 2 OC 2 Il5 is formed, rather 

 than the tribromnitroresorcine diethylether, C 6 Br 3 N0 2 (OC 2 H 5 ) 2 . 

 Our previous work had led us to the conclusion that the presence of 

 a trace of water is favorable to the formation of the phenetol, as 

 on one occasion when benzol not dried over sodium was used this 

 substance was obtained, and in the experiment described in our 

 previous paper which yielded a quantity of the phenetol common 

 benzol was also used, whereas in all the preparations made by us 

 with absolute benzol and alcohol not a trace of the phenetol has been 

 found. On the other hand, in a repetition of the experiment with 

 common benzol, and in one in which undried benzol and common 

 instead of absolute alcohol were used only the resorcine ether 

 C G Br 3 lSr0 2 (OC2H 5 ) 2 was isolated. To test this question still fur- 

 ther, we repeated the experiment described at the beginning of this 

 section, using carefully dried acetic ester instead of the commercial 

 article, and obtained decidedly less of the phenetol with a large 

 proportion of the tribromnitroresorcine diethylether, thus confirm- 

 ing, although not absolutely proving, our previous inference that 

 the presence of a trace of moisture is favorable to the formation of 

 the phenetol. 



* These Proceedings, XXV. 185. 



