OF ARTS AND SCIENCES. 197 



the baric malonate was converted into the lead salt, and the latter 

 analyzed. 



0.5179 gnu. of the salt, dried at 110°, gave, on ignition with HgSO^, 

 0.5062 grm. PbSO,. 



Calculated for PbCsHjO^. Found. 



66.99 66.79 



The amount of baric malonate formed in this decomposition with an 

 excess of baric hydrate was found to be forty-nine per cent of the 

 theoretical yield as the mean of two determinations. 



The behavior of the acid towards hydrobromic acid was studied by 

 Mr. C. F. Mabery. It is not altered by ordinary concentrated hydro- 

 bromic acid (b. pt. 126°), nor is it affected in the cold by an acid 

 saturated at 0° ; but it forms an addition-product when heated with 

 it for several hours at 100°. The reaction is by no means neat, and a 

 large portion of the substance is charred. The tribrompropionic acid 

 which is thus formed differs essentially in its melting-point (116- 

 117°) and other physical properties from the acid melting at 93° men- 

 tioned by Linnemann and Penl,* and recently more fully described 

 by Michael and Norton ; f and also from the acid melting at 53°, 

 which was obtained by Fittig and Petri,t by the action of hydro- 

 bromic acid upon their dibromacrylic acid. It is sparingly soluble in 

 cold water, readily in hot, and may be crystallized without difficulty 

 from hot water. It is readily soluble in alcohol or ether, somewhat 

 less soluble in chloroform. From water it crystallizes in pearly 

 scales, which melt at 116-117°. Argentic nitrate precipitates from 

 an aqueous solution of the acid, the silver salt in clustered rhombic 

 plates. 



0.1892 grm. of the acid gave 0.3453 grm. AgBr. 



Calculated for CgHjErgOa. Found. 



Br 77.16 77.64 



If one molecule of bromine is added to dibromacrylic acid dissolved 

 in chloroform, the color of the bromine gradually disappears, and after 

 the lapse of some time tetrabrompropionic acid separates in large, 

 well-formed crystals, which melt at 125°. This acid is at present 

 under investigation in this laboratory. 



* Berichte der deutsch. chem, Gesellsch., viii. 1098. 



t Amer. Chem. Journ., ii. 18. 



J Ann. Chem. u. Pharm., cxcv. 73. 



