32 



Brands Showdng a Commercial Shortage of|$l or over per Ton. 



1 Two analyses made. 



2 Two samples collected at Easthampton had valuations and commercial shortages as follows: S37.70 

 and $2.30; $38.18 and $1.82. 



' Collected at Framingham. Commercial valuation $37.95, and commercial shortage $2.05 per ton. 

 " Two samples collected at Framingham had valuations and commercial shortages as follows : $36.45 

 and $3.55; $36.26 and $3.74. 



Carbonate of Potash and Sulfate of Potash-Magnesia. 



Manufacturer 



Material 



Number 



of 

 Samples 



Potash 



Found 



Guaran- 

 teed 



Chlorine 



A. W. Higgins, Inc. 



The Berkshire Fertilizer Co. 



Carbonate of Potash 

 Sulfate of Potash-Magnesia 



66.72 

 29.801 



62.00 

 26.00 



1.98 



1 The product contained 12.00% magnesium oxide, equivalent to 35.82% magnesiiim sulfate. 



The relatively large amount of clilorine found in the high-grade sulfate of potash 

 sold in the state indicates that the producers are not refining this product, as used 

 in the fertilizer trade, to the same degree as in 1924 when this laboratory found 

 only 2.13 per cent of chlorine as the average for nine analj^ses. A study of this 

 year's inspection of this salt indicates the use of two different grades or degrees of 

 refinement. Six analj^ses (10 samples representing 46 tons sold) showed a range 

 from 1.05 to 2.56 per cent of chlorine, with an average of 1.83 per cent, equivalent 

 to 2.44 per cent of potash, the average total water soluble potash being 50.50 per 

 cent. Five other analyses (8 samples representing 139 tons sold) showed a range of 

 chlorine from 3.53 to 3.95 per cent, ^vith an average of 3.71 per cent, equivalent to 

 4.93 per cent of potash, the average total water soluble potash being 49.47 per cent. 



At a recent meeting of the Association of Official Agricultural Chemists, the 

 Committee on Definition of Terms and Interpretation of Results on Fertilizers 

 tentatively defined sulfate of potash and set a maximum for chlorine permissible 

 in fertilizer mixtures in which the potash is claimed as sulfate, as follows: 



"Sulfate of potash is a potash salt containing not less than forty-eight per cent 

 (48 %) of potash (K2O) in form of sulfate and not more than two and one-half per 

 cent (2.5%) of chlorine." 



Maximum amount of chlorine permissible in fertilizers in which the potash is 

 claimed as sulfate: 



"The chlorine in mixed fertilizers in which the potash is claimed as sulfate shall 

 not exceed three-tenths of one per cent (.3%) more than what is called for in the 

 minimum potash content based on the definition for sulfate of potash as formulated 

 by the committee, calculated as follows: 0.05 times the percentage of potash found 

 plus 0.3." 



These definitions were formulated after a full and free discussion of the subjects 

 in open meeting at which several trade chemists voiced the opinion that 2.5 per 

 cent of chlorine in sulfate of potash was a liberal allowance. It seems that the 

 fertilizer manufacturer would be justified in asking for a better refined product, as 

 according to the above definition the group of potash salts containing an average 



