172 PROCEEDINGS OP THE AMERICAN ACADEMY 



brown and gave out the sharp, penetrating odor mentioned above. 

 Analyses I. and II. were made with a preparation crystallized from 

 water without subsequent washing, III., IV., and V. with substance 

 washed with ether. 



I. 0.9479 grm. gave 0.5018 grm. COo and 0.0547 grra. 11,0. 



II. 0.3434 grm. gave, on ignition with HgSO^, 0.1165 grm. BaSO^. 



III. 0.4186 grm. gave, on ignition, 0.1482 grm. BaSO^. 



IV. 0.5747 grm. gave, on ignition, 0.2030 grm. BaSO^. 

 V. 0.7638 grm. gave, on ignition, 0.2695 grm. BaSO^. 



Calculated for Ba(C4HBr203)2. Found. 



I. n. m. IV. V. 



C 14.74 14.44 



H 0.30 0.63 



Ba 21.04 19.95 20.82 20.77 20.74 



This salt is readily soluble even in the cold water, and soluble 

 also in alcohol. On boiling its aqueous solution, the decomposition 

 described above ensues, with the evolution of carbonic dioxide. This 

 reaction has not yet been farther studied. 



Argentic Mucobromate, AgC^HBrjOg. The silver salt may be. made 

 by adding a concentrated solution of argentic nitrate to a solution 

 of the barium salt. Since it is quite soluble even in cold water, it 

 is better to use, instead of the barium, the calcium salt, in order to 

 facilitate washing. It is precipitated in fine, felted needles, which 

 blacken quite rapidly on exposure to diffused light, and are decom- 

 posed at once on moistening with alcohol or warming with water ; 

 argentic bromide is formed, together with some metallic silver. This 

 substance was dried in vacuo for analysis : — 



I. 0.8601 grm. gave 0.1862 grm. AgBr. 

 II. 0.5640 grm. gave 0.2903 grm. AgBr. 



Calculated for AgCiUBroOa. Found. 



I. ir. 



Ag 29.59 29.70 29.56 



Ethyl Mucobromate. The ethyl ether of mucobromic acid may 

 readil}' be made by saturating its solution in absolute alcohol with 

 hydrochloric acid, or more conveniently by warming this solution with 

 concentrated sulphuric acid. If considerable sulphuric acid be used, 

 the ether often crystallizes out on standing in large, well-formed crys- 

 tals, otherwise it is precipitated by the addition of water and washed 



