OF ARTS AND SCIENCES. 329 



Baric Macoxycldorate^ BaC^HClO^ . 2 II2O. — The preparation of 

 the barium salt has ah-eady been described. It is sparingly soluble 

 in cold water, more readily in hot, and is nearly insoluble in dilute 

 alcohol. Although it is decomposed by heating its aqueous solution, 

 the decomposition is not particulai'ly rapid, and small quantities of the 

 salt may be recrystallized from hot water with little difficulty. It 

 crystallizes then in fine clustered needles, and is obtained in the same 

 form by precipitating its aqueous solution with alcohol. In evaporat- 

 ing a cold aqueous solution in vacuo over sulphuric acid, the salt may 

 be obtained in long lustrous prisms with perpendicular terminations. 

 The salt crystallized from water, or precipitated by alcohol, when air- 

 dried, loses over sulphuric acid somewhat more than one molecule of 

 water, and has then the composition BaC^HClO^ . H2O. 

 I. 2.5352 grm. of salt recrystallized from water and dried by ex- 

 posure to the air lost over sulphuric acid 0.1706 grm. HoO. 

 11. 2.2127 grm. of salt recrystallized from water and dried by ex- 

 posure to the air lost over sulphuric acid 0.1480 grm. HoO. 



III. 1.9160 grm. of salt precipitated by alcohol and dried by exposure 



to the air lost over sulphuric acid 0.1288 grm. HoO. 



IV. 1.5273 grm. of salt precipitated by alcohol and dried by exposure 



to the air lost over sulphuric acid 0.1054 grm. H2O. 



1 H2O 



The salt dried over sulphuric acid contained a percentage of barium 

 agreeing closely with that required by the formula, BaC^HClO^ . H2O. 

 It lost weight slowly at 100-105°, but only the compact salt crystallized 

 from water could be brought to constant weight at this temperature 

 without essential decomposition.. The voluminous salt precipitated by 

 alcohol after many weeks still lost in weight, contained baric chloride, 

 and had become badly discolored. 



I. 1.4644 grm. of salt recrystallized from water and dried over 



sulphuric acid lost, at 100-105°, 0.0820 grm. H2O. 

 II. 1.4771 grm. of salt recrystallized from water and dried over 

 sulphuric acid lost, at 100-105°, 0.0827 grm. HgO. ' 



III. 0.8947 grm. of salt recrystallized from water and dried over 



sulphuric acid gave 0.6871 grm. BaSO^. 



IV. 0.5865 grm. of salt recrystallized from water and dried over 



sulphuric acid gave 0.4498 grm. BaSO^. 

 V. 0.3261 grm. of salt precipitated by alcohol and dried over sul- 

 phuric acid gave 0.3266 grm. BaSO^. 



