JACKSON AND KOCH. — TRIBROMDINITROBENZOL. 129 



gave no test for a nitrite, showing that the nitro groups had not been 

 attacked. 



Other Products of the Reaction. — During the purification of the dini- 

 troresorcine diethylether a small quantity of the bromdinitroresorcine 

 diethylether melting at 184" was isolated. Its presence shows that the 

 heating for ten minutes used by us was not sufficient to convert the whole 

 of it into the dinitroresorcine diethylether. 



From the ligroin mother liquors of the bromdinitroresorcine diethyl- 

 ether melting at 92°, a few milligrams of a body were obtained, which 

 melted constant at 112°, contained bromine, and gave no test for nitro- 

 gen after fusion with sodium.* AVe supposed, therefore, that we had 

 the tribromresorcine, which melts according to Benedikt at 111°, and 

 could be formed by the replacement of the two nitro groups by ethoxy 

 radicals, followed by saponification : but upon comparing our specimen 

 with some tribromresorcine made for this purpose, it was found that, 

 although the two substances melted at the same point, (as we found 

 the melting point 11 2*^-1 13° for the tribi'omresorcine,) they differed 

 markedly in solubility in alcohol, our substance being much the less solu- 

 ble, and also in the method of crystallization, although the forms were 

 not incompatible. That our substance was not tribromresorcine was 

 proved by the action of sodic hydrate, which did not affect our body, 

 whereas it dissolved the tribromresorcine instantly, giving a solution 

 which turned black almost at once. The amount of our substance was 

 not enough for analysis, so we can make no statement in regard to its 

 nature. We add a description of its crystalline form, which may lead to 

 its identification. It forms when crystallized from alcohol white very 

 sharp needles, which when better developed appear as slender prisms 

 with square ends or bluntly sharpened by several planes at very obtuse 

 angles to the sides and terminated by a basal plane. When less well 

 developed, it forms felted masses of needles or bunches, or long sheaves 

 of needles. None of the arborescent forms were observed which seemed 

 to be characteristic of the tribromresorcine. This substance was also 

 characterized by its solubility in ligroin. It was only formed in very 

 minute quantities under the conditions of the reaction used by us. 



The Products of the Reaction soluble in Water. 



The wash waters obtained from the product of the action of sodic 

 ethylate on tribromdinitrobenzol at 70° were highly colored, but the 



* We do not feel that this proves the substance is free from nitrogen. 



VOL. XXXIV. — 



