JACKSON AND EARLE. TRIBROMTR1NITROBENZOL. 237 



filtrate allowed to evaporate spontaneously ; the residue was washed with 

 water until the washings were colorless, and then recrystallized from 

 alcohol until it showed a constant melting point, which was found to be 

 121°. The melting point of styphnic ethylether, 



C 6 H(OC 2 H 5 ) 2 (N0 2 ) 3 (OC 2 H 5 ) 2 1.8. (N0 2 ) 3 2.4.6, 

 is given as 120°. 5, and it is described as forming long plates, which 

 quickly turn orange-brown in the light ; our substance crystallized in 

 prisms connected by their longer sides, and turned brown by exposure to 

 the light. It contained no bromine. There can be no doubt, therefore, 

 that the two bodies are identical, and that this styphnic ether formed by 

 replacing each bromine by an ethoxyl group is the principal product of 

 the reaction. It was not, however, the only product of the action of sodic 

 ethylate on dibromtriuitrobenzol, as the reaction product insoluble in the 

 organic solvents but soluble in water gave tests for nitrite as well as 

 bromide, and the aqueous washings were colored ; but the amount of these 

 secondary products was so small that they could not have been studied 

 without preparing the mother substance on a very large scale, and the 

 importance of the subject did not warrant the great expenditure of time 

 which would have been necessary for this purpose. 



Action of Sodic Ethylate on Adjacent Tribromdinitrobenzol. 

 Seven grams of the tribromdinitrobenzol (Br 3 1 . 2 . 3 . (N0 2 ) 2 4. 6) 

 were dissolved in 70 c.c. of benzol, and mixed with sodic ethylate in the 

 proportion of three molecules of the ethylate to each molecule of the tri- 

 bromdinitrobenzol. The sodic ethylate was prepared by adding the cal- 

 culated amount of sodium to 70 c.c. of absolute alcohol. A deep red 

 turbid solution was formed immediately, which was allowed to stand in 

 a corked flask at ordinary temperatures for two days, and then filtered, 

 the filtrate allowed to evaporate spontaneously, and the residue washed 

 with water, until the washings were colorless. The portion insoluble in 

 water after recrystallization from alcohol showed the constant melting 

 point 58°, and crystallized in long white needles turning yellow in sun- 

 light, but was formed in such small quantity that there was not enough 

 for analysis ; we, therefore, sought the principal product of the reaction 

 in the portion soluble in water. The precipitate formed during the 

 action of the sodic ethylate was dissolved in water, and mixed with the 

 wash waters, which had previously been concentrated to a convenient 

 bulk. The solution was then acidified with acetic acid, which threw 

 down a black tarry precipitate. This was filtered out, washed, sus- 

 pended in water, and dissolved by adding sodic hydrate to neutralization ; 



