280 



PROCEEDINGS OF THE AMERICAN ACADEMY 



I. 0.2000 grra. of the substance gave 0.5235 grm. AgBr + AgCL 

 IL 0.5874 grra. of the substance gave 0.2732 grm. COg and 

 0.0268 grm. H,0. 

 III. 0.5385 grm. of the substance gave 0.2330 grm. CO^.* 



76.26 



The salts of this acid are extremely unstable. It dissolves readily 

 in sodic or potassic carbonate, or in ammonic hydrate, and is precipi- 

 tated by hydrochloric acid ; yet the corresponding salts could not be 

 prepared sufficiently pure for analysis. When treated with baric car- 

 bonate, the acid dissolves with the formation at first of a clear solution ; 

 but soon the latter becomes turbid from the separation of an oil, which 

 continues until the decomposition of the salt is complete. Although 

 this oil was not submitted to analysis, it is probably tetrachlorethylen. 

 The silver salt which is formed when argentic nitrate is brought in 

 contact with the acid, soon changes color, even in the dark, and all 

 attempts to prepare it in a form suitable for analysis were unsuccessful. 



Unless a molecular rearrangement takes place during the addition 

 of chlorine, which does not seem at all probable, the structure of this 

 acid must be represented by the formula : — 



CBrClj 



CCI, 

 I 

 COOH. 



Many variations of the method of preparation above described have 

 been tried in order, if possible, to limit the addition of chlorine to the 

 formation of a bromdichloracrylic acid. The appearance of the product 

 and its behavior toward solvents at different stages of the chlorina- 

 tion would seem to indicate that each molecule of brompropiolic acid 

 absorbed two molecules of chlorine, thereby forming a mixture of 

 bromtetrachlorpropionic acid and unaltered brompropiolic. This 

 would, of course, preclude the possibility of obtaining by the addition 

 of chlorine the corresponding substituted acrylic acid. 



* By accident tlie water in this combustion was lost. 



