192 COTTON PLANTER'S MANUAL. 



two days, after which it was filtered and washed out with 

 water containing one-eighth of ammonia, and bufned until it 

 was white. It gave 0'30 1 grammes of 2MgO, P0 5 (pyro- 

 phosphate of magnesia), or for the entire liquid, 0'903 grammes 

 = 0*330 grammes MgO (magnesia). 



B. 



The solution B was precipitated while boiling with chloride 

 of barium, and left standing on a sand-bath for twenty-four 

 hours, then filtered and washed with boiling water, dried, and 

 burned. It gave 0'079 grammes sulphate of barytes (BaO, 

 SO,), or for the entire liquid, 0'237 grammes (BaO, S0 3 ) 

 = 0-081 grammes sulphuric acid (S0 3 ). 



The liquid filtered from the precipitate of BaO, S0 3 , was 

 mixed with per-chloride of iron and acetate of soda, and boil- 

 ed for five minutes in a large flask ; then the precipitate of 

 phosphate of iron, and basic acetate of iron, was filtered while 

 warm, and washed with boiling water, until on evaporating a 

 drop of the filtrate there remained no residue. 



The precipitate was dissolved while moist, in as small a 

 quantity of muriatic acid as possible. Tartaric acid and am- 

 monia were now added in excess, when to the clear yellow- 

 colored solution, a mixture of sulphate of magnesia and chloride 

 of ammonia was added, to prevent a precipitate of magnesia. 

 The precipitate was left standing for two days, after which it 

 was filtered and washed out with water containing ammonia. 

 When dried, burned and weighed, it gave 0'442 grammes of 

 2MgO, P0 5 , or for the entire liquid, 1'326 grammes of 2MgO, 

 P0 6 = 0'837 grammes phosphoric acid (P0 3 ). 



C. 



Baryta water was added to this solution, until an alkaline 



