238 PROCEEDINGS OP THE AMERICAN ACADEMY. 



The study of the red flocculent precipitate obtained by the addition 

 of sulphuric acid to an aqueous solution of the sodium salt of tribrom- 

 resorcine has not led to any trustworthy results. Treatment with 

 water and ether showed that it was not homogeneous, and the different 

 fractions thus obtained could not be brought into a state fit for analysis, 

 as no means of proving that they were pure could be found. Some 

 of these analyses gave numbers agreeing fairly well with the very 

 probable formula [C 6 H 2 P>rOH] 2 2 ; but for the reason just given it is 

 impossible to accept this formula as established by them. 



Tribromresorcine when treated with aqueous sodic carbonate dis- 

 solves with the evolution of carbonic dioxide, the solution immediately 

 blackening, as has been stated already ; upon acidification with dilute 

 sulphuric acid a reddish brown flocculent precipitate was formed similar 

 to that mentioned above, and the clear filtrate from this body gave a 

 very heavy test for bromides. That in this case the blackening was 

 not due to oxidation was shown by the fact that it took place in an 

 atmosphere of hydrogen, even when the solution had been boiled to 

 insure the absence of dissolved oxygen. Sodic or potassic hydrate 

 has the same effect upon tribromresorcine as the carbonate. The red 

 precipitate obtained upon acidifying has not yet been obtained in 

 crystals, and when heated decomposed without melting, giving off 

 hydrobromic acid. This body is doubtless the same as that obtained 

 by the action of water on tribromresorcine, and also from the black- 

 ened sodium salt by acidifying its aqueous solution, as has been 

 described above. 



Action of Sodium Malonic Ester on Tribromresorcine. 



This reaction was taken up to see if another case of the peculiar 

 substitution of bromine by hydrogen, already noticed by one of us,* 

 could not be obtained. After a great many trials the best mode for 

 studying the reaction was found to be as follows. Five grams of 

 sodium were dissolved in 250-300 c. c. of absolute alcohol, and to this 

 were added thirty-five grams of malonic ester. Twenty-five grams of 

 tribromresorcine were then added, and this turned dark and afterward 

 dissolved. After boiling; the mixture for three hours in a flask fitted 

 with an inverted condenser, the alcohol was distilled off and the con- 

 tents of the flask were acidified with dilute sulphuric acid. A dark red 

 oil separated, which was dissolved in ether, this solution then dried over 

 calcic chloride, and the ether distilled off. Upon standing several 



* These Proceedings, XXIV. 1, 256. 



