164 PROCEEDINGS OF THE AMERICAN ACADEMY 



flat, clustered prisms, which melted at 57-58°, and boiled with decided 

 decomposition at 271—272"^ (mercury column completely in vapor), 

 under a pressure of 7G5 mm. The ether has a pleasant, fragrant 

 odor, not unlike that of ethyl pyromucate. It is readily soluble in 

 ether, chloroform, benzol, or ligroin, somewhat less soluble in carbonic 

 disulphide. It is readily soluble in hot alcohol, much more sparingly 

 soluble in cold. The ether used in Analysis II. was made from the 

 silver salt. 



I. 0.1524 grm. substance gave 0.1927 grm. AgBr. 

 11. 0.2024 grm. substance gave 0.2556 grm. AgBr. 



Br 



Ph-Dibrompyromucyl Bromide, C^HBrgOg. — It has already been 

 said that /?8-dibrompyromucyl bromide is formed by the action of dry 

 bromine upon pyromucic acid. In order to isolate it, we submitted 

 the viscous oil which was thus formed to fractional distillation in 

 vacuo. After repeated distillations a fraction was isolated, boiling 

 at 149-155° under a pressure of 24 mm., most of which passed over 

 between 153° and 155°. This fraction, on standing over sulphuric 

 acid, gradually f^olidified, and the solid thus obtained could readily be 

 purified by recrystallization from ligroin. On heating with water it 

 formed /88-dibrompyromucic acid ; with alcohol, it gave the ether melt- 

 ing at 56-57°; and on analysis it gave the percentage of bromine required 

 by the formula C^HBi-gOa. Analysis III. was made with material pre- 

 pared from the crude product by crystallization alone without previous 

 distillation. 



I. 0.2214 grm. substance gave 0.3752 grm. AgBr. 



II. 0.1876 grm. substance gave 0.3180 grm. AgBr. 



III. 0.2152 grm. substance gave 0,3640 grm. AgBr. 



Br 



The /58-dibrompyromucyl bromide crystallizes in small compact 

 I^risms which melt at 45-46°. It is readily soluble in alcohol, ether, 

 chloroform, or benzol, somewhat less soluble in ligroin. It is slowly 

 attacked by cold water, more readily by hot. 



From the lower fractions there separated, on standing, prismatic 

 crystals, which, from their behavior and from their melting-point 



