200 PROCEEDINGS OF THE AMERICAN ACADEMY 



weight of cold water, and the vapor of bromine is slowly passed 

 in by means of a current of air, the color of the bromine is quickly 

 discharged, and the acid goes into solution with the escape of car- 

 bonic dioxide. When exactly two molecules of bromine have been 

 added, the whole is allowed to stand for a short time, and the col- 

 orless solution then thoroughly extracted with ether. The ether 

 left upon evaporation a crystalline body which was recrystallized 

 from boiling benzol, and finally from water. An analysis showed 

 that the formula of the substance was C 5 H c 3 . 



0.2461 grm. substance gave 0.4734 grm. C0 2 and 0.1185 grm. 

 H 2 0. 



Calculated for C 6 H 6 3 . Found. 



C 52.64 52.47 



H 5.26 5.35 



The new body was readily soluble in hot water, more sparingly 

 soluble in cold water, and was acid in its character. It dissolved 

 readily in alcohol, ether, or boiling chloroform, more sparingly in 

 cold chloroform. In hot benzol it was quite readily soluble, and 

 very sparingly soluble in cold benzol, carbonic disulphide, or ligroin. 

 It crystallized in long slender lustrous needles, which melted at 

 122-123°. Recrystallization from various solvents failed to raise 

 the melting point, but after several careful sublimations it melted 

 at 123-124°. The formula of this acid was further controlled by 

 an analysis of its silver salt, which was prepared by the cautious 

 addition of ammonic hydrate to a solution of the acid containing 

 argentic nitrate. The salt can be recrystallized from boiling wa- 

 ter without difficulty, and forms concentrically clustered six-sided 

 plates. 



I. 0.2237 grm. salt gave 0.1901 grm. AgBr. 

 II. 0.2926 grm. salt gave 0.2484 grm. AgBr. 



Calculated for Found. 



AgC B H 5 3 I. II. 



Ag 48.87 48.81 48.76 



The acid which had thus been formed from methylpyromucic 

 acid corresponded well with the description of the acetacrylic acid 

 which Wolff * had shortly before made through the decomposition 

 of /3-bromlaevulinic acid. Its melting point, however, was given 



* Berichte der deutsch. chem. Gesellsch., XX. 426. 



