AGRICULTURAL ANALYSIS 

 TABLE SHOWING PERCENTAGE OF POTASH IN FERTILIZERS. Cont. 



Moore's Method 



Official 

 No. method. 



1759 4.98 



1761 0.92 



1762 0.70 



1763 5-70 



2119 3.88 



2120 3.60 



2911 3.96 



2912 4.08 



As a rule, the results are slightly higher by the moore method 

 than by the official method; this is only noticeably so in case of 

 sample 1/63. From this it would appear that the flocculent pre- 

 cipitate of iron and lime phosphate has but little to do with the 

 low results usually obtained. It is to be noticed that only when 

 the acid alcohol is used may the impurities contained in the plati- 

 num precipitate be neglected. Where plain alcohol is used it is 

 usually necessary to dissolve the potassium chlorplatinate, wash, 

 and re-weigh the crucible to obtain the true weight of the potash. 



It is obvious that after igniting the material it is not suffi- 

 cient to treat it with water alone in order to dissolve the potash ; 

 such procedure does not always secure all the potash, some of it 

 remaining undissolved, possibly in complex silicates or phospho- 

 silicates, adhering to the dish. It was found that the potash so 

 held could usually be readily recovered by dissolving the ignited 

 material in the dish in dilute hydrochloric acid. This is not 

 always true, however, the potash so held being dissolved but 

 slowly in some instances, and while it appears that all potash may 

 be recovered by prolonged treatment, the process is not con- 

 sidered to have any advantages over the official method. 



478. Estimation of Potash by the Platinum Method in the 

 Presence of Sulfates of the Alkalies and Alkaline Earths. Regel 



