42 PROCEEDINGS OP THE AMERICAN ACADEMY 



The barium, calcium, and potassium salts of this acid were made 

 and analyzed. We were unable to prepare the silver salt in a form 

 sufficiently pure for analysis. Argentic bromide began to separate 

 even in the dark as soon as the salt was formed. 



Baric tetrabrompropionate, Ba(C3HBr^02)2 . \ H^O ? To prepare 

 this salt, a solution of the acid was saturated with baric carbonate, 

 filtered, and allowed to evaporate spontaneously at the ordinary tem- 

 perature. 



From the concentrated solution the salt crystallized in flat prisms, 

 which were very soluble in water. In aqueous solution the salt is per- 

 manent when exposed to the air at ordinary temperatures, but it is 

 rapidly decomposed by heat. In the following determinations of the 

 water of crystallization, in each case the salt was dried to a constant 

 weight in the air and then heated until constant at 80°. 



I. 1.2784 grms. of the air-dried salt lost 0.0090 grm. Ylf> at 80°. 



11. 1.0862 grms. of the air-dried salt lost 0.0081 grm. \\p at 80°. 



III. 1.2403 grms. of the air-dried salt lost 0.0087 grm. HgO at 80°. 



Calculated for Ba(C3HBr402)2 . * HjO. Found. 



I. II. III. 



H^O .96 .7 .7 .75 



1.0762 grms. of the salt dried at 80° gave 0.2747 grm. BaSO^. 



Calculated for Ba(C3HBri02)2. Found. 



Ba 14.97 • 15.01 



Calcium tetrahrompropionate, Ca(CgHBr^0o)2 • H„0. When an aque- 

 ous solution of the acid was neutralized with calcic carbonate in the 

 cold and evaporated at the ordinary temperature, the calcium salt sep- 

 arated from the concentrated solution in clusters of miscroscopic prisms, 

 which were much less soluble in water than the corresponding barium 

 salt. The air-dried salt contained one molecule of water of crystalliza- 

 tion, which was given up at 80°. 



I. 1.1413 grms. of the air-dried salt gave 0.0215 grm. H.O at 80°. 

 II. 1.1087 grms. of the air-dried salt gave 0.0205 grm. H.O at 80°. 

 III. 1.0948 grms. of the anhydrous salt gave on ignition with HgSO^ 

 0.1895 grm. CaSO^. 



