326 PROCEEDINGS OF THE AMERICAN ACADEMY 



closely resemble the corresponding bromine derivative. It dissolves 

 readily in alcohol, ether, or hot benzol, but sparingly in cold benzol. 

 The acid recrystallized from benzol melted at 176-177°, and a prepa- 

 ration made from the pure etbyl ether melted at the same point. Its 

 solubility in cold water was determined according to the method of 

 V. Meyer. A weighed portion of the solution saturated at 19°. 5 

 was boiled with baric carbonate, and the barium dissolved determined 

 by precipitation with sulphuric acid. 



I. 37.8458 grm. solution saturated at 19°.5 gave 0.0833 grm. BaS0 4 . 

 II. 33.5216 grm. solution saturated at 19°.5 gave 0.0742 grm. BaS0 4 . 



According to these determinations, the solution saturated at 19°. 5 

 contained the following percentages of acid. 



i. n. 



0.28 0.28 



Baric S Chlorpyromucate, Ba(C 5 H 2 C10„) 2 . H 2 0. — The barium salt 

 was prepared by boiling the acid with an excess of baric carbonate. 

 The salt is quite readily soluble even in cold water, still more readily 

 soluble in hot water, and separates from a hot concentrated solution 

 in thin leafy plates, usually aggregated in globular form. The air- 

 dried salt contains one molecule of water, which it loses rapidly at 100°. 



I. 1.2193 grm. air-dried salt lost at 100° 0.0491 grm. H 2 0. 

 II. 0.5932 grm. air-dried salt gave 0.3094 grm. BaS0 4 . 



Calculated for Found. 



Ba(C 5 H 2 C10 3 ) 2 . H 2 0. I. II 



H 2 4.04 4.04 



Ba 30.72 30.67 



0.6909 grm. salt dried at 100° gave 0.3763 grm. BaS0 4 . 



Calculated for 



Ba(C 5 II 2 C10 3 ) 2 . Found. 



Ba 32.01 32.02 



The solubility of the salt in cold water was determined according 

 to the method of V. Meyer. 



I. 9.3523 grm. solution saturated at 19°.5 gave 0.2932 grm. BaS0 4 . 

 II. 8.3395 grm. solution saturated at 19°.5 gave 0.2534 grm. BaS0 4 . 



The solution saturated at 19.5° therefore contained the following 

 percentages of anhydrous salt. 



I. n. 



5.76 5.58 



