OF ARTS AND SCIENCES. 209 



I. 0.2152 grin, substance gave 0.2758 grin. C0 2 and 0.0490 grm. 

 H 2 0. 

 II. 0.1176 grm. substance gave 0.1079 grin. AgBr. 



Found. 

 I. II. 



34.95 

 2.53 

 Br 39.02 39.04 



Tbe a-brommethylpyromucic acid crystallizes in small clustered 

 oblique plates which melt at 147-148°. It is readily soluble in 

 alcohol, ether, glacial acetic acid, or acetone, somewhat sparingly 

 soluble in boiling benzol or chloroform, from which solvents it 

 crystallizes well on cooling. In boiling toluol it is freely soluble, 

 sparingly soluble in the cold, and almost insoluble in carbonic di- 

 sulphide. It is but slowly acted on by cold water, but on warming 

 it is readily dissolved with decomposition. The solution contains 

 hydrobromic acid in abundance, and upon evaporation a crystalline 

 acid is obtained, which is free from bromine. This behavior, which 

 is in such striking contrast with the extreme stability of the de- 

 rivatives of pyromucic acid that contain halogen, sufficiently estab- 

 lishes the position of the bromine in the side-chain. It also 

 effectually prevented the preparation of its salts by the ordinary 

 methods. 



Decomposition by Water. 



The product formed by the action of water upon a>-brommethyl- 

 pymmucic acid we have studied a little more in detail. After 

 heating an aqueous solution for some time at 100° it was evaporated 

 over lime in vacuo. The hard black crystalline residue was dis- 

 solved in hot water, filtered from the separated carbon, and again 

 evaporated. The brownish vitreous crystalline mass thus obtained 

 melted with decomposition at 158-162°, and by recrystallization 

 from a mixture of toluol and absolute alcohol the melting point 

 could be raised to 162-163°, although the body still melted with 

 decomposition. A combustion showed that the substance was w- 

 oxymethylpyromucic acid. 



0.2623 grm. substance gave 0.4870 grm. C0 2 and 0.1052 grm. 

 H 2 0. 



Calculated for C 6 H 6 4 . Found. 



C 50.70 50.63 



H 4.23 4.46 



VOL. XXVII. (n. S. XIX ) 14 



