OF ARTS AND SCIENCES. 149 



readily decomposed by heat, but may be dried for analysis over sul- 

 phuric acid. 



0.4950 grm. of the salt gave on precipitation with HCl 0.1731 grm. 

 AgCl. 



Calculated for AgCgHCliBraOa . Found. 



Ag 26.46 26.31 



Baric § Dichlordibrompropionate, Ba(C3lICl2Br202)2. 2H2O. The 

 barium salt which we made by neutralizing an aqueous solution of the 

 acid with baric hydrate crystallized on spontaneous evaporation of its 

 solution in long radiating needles which were very soluble in cold 

 water. When dried by exposure to the air the salt proved to contain 

 two molecules of water which it lost over sulphuric acid. 



I. 1.6201 grm. of the air-dried salt lost over H2S0^ 0.0705 grm. 

 14,0. 

 II. 1.5443 grm. of the air-di-ied salt lost over H2SO4 0.0731 grm. 

 H2O. 



Calculated for Ba(C3HCl2Br202)2 • 2 ttjO. Found. 



I. II. 



H2O 4.66 4.35 4.74 



0.8236 grm. of the salt dried over HgSO^ gave 0.2619 grm. BaSO^. 



Calculated for Ba(C3HCl2Br202)2 . Found. 



Ba 18.59 18.63 



These results prove that the « and (3 dichlordibrompropionic acids 

 described are essentially different. 



The barium salt was readily decomposed by warming its aqueous 

 solution. Baric chloride and carbonic dioxide were formed together 

 with a colorless oil which undoubtedly was a dibromchlorethylen. 

 With bromine this oil gave a solid addition product, which, however, 

 we have not as yet prepared in quantity sufficient for complete purifi- 

 cation and identification. 



