64 PROCEEDINGS OP THE AMERICAN ACADEMY, 



Properties of Trihromnitrophenetol. — These were given in our first 

 paper as the properties of tribrouiresorcine ; we therefore think it best 

 to repeat them here under the true name. It crystaUizes from alcohol 

 in long white pearly plates terminated by two planes at an acute angle, 

 which is usually truncated by a basal plane. It melts at 158°. It is 

 nearly insoluble in cold alcohol, soluble in hot; soluble in chloroform, 

 benzol, or acetone ; slightly soluble in cold ligroin, more soluble in hot. 

 The best solvent for it is hot alcohol. 



In the aqueous filtrate fi'om the trihromnitrophenetol we found the 

 salt of a diatomic phenol melting at 67°, to which in our previous paper 

 we assigned the formula C6HBr(N02)2(OH)o, on the ground of a bromine 

 determination. In returning to the subject we thought it well to obtain 

 more analytical data in regard to it, and for this purpose we have made 

 and analyzed the barium salt. 



Barium Salt of Bromdinitroresorcine(?), C6HBr(N02)202Ba. 



The constitution of the phenol has not been proved ; but, as according 

 to analogy the two hydroxyls should be in the meta position to each 

 other, we have adopted the name given above provisionally. 



The barium salt was prepared as follows. Two grams of the phenol 

 were mixed with a freshly prepared alcoholic solution of sodic ethylate, 

 and then treated with an aqueous solution of baric chloride. The yellow 

 precipitate thus obtained was filtered as quickly as possible, washed three 

 times Avith a little cold water, and once with ether, and then dried at 

 130°, and analyzed with the following result : — 



0.2580 gram of the salt gave 0.1464 gram of baric sulphate. 



Calculated for CeHBrCNOjJaOaBa. Found. 



Barium 33.09 33.36 



This analysis, therefore, confirms our previous view of the composition 

 of the phenol. 



Properties. — The barium salt is an orange-yellow powder with no 

 well defined crystalline form. When heated in the fiame of a Bunsen 

 lamp, it explodes. It is soluble in water, and its solubility is increased 

 by heat ; slightly soluble in alcohol ; insoluble in ether, chloroform, or 

 ligroin. Acids set free the phenol CeIIBr(N02)2(OH)2 from it. 



