12 CONTROL SERIES No. 90 



Explanation of Tables of Analyses. 



Guarantee. The plant food guarantee or the grade of each fertilizer is 

 made a part of the trade name under the heading "Name of Manufacturer 

 and Brand," and is expressed as nitrogen, available phosphoric acid and 

 water soluble potash and in that order. 



Commercial Shortages. In the table designated "Mixtures showing a 

 commercial shortage of $1 or more per ton," the column headed "Approximate 

 commercial valuation per ton" gives the sum of the valuation of each plant 

 food element computed from the analysis by use of the trade values adopted 

 by the Massachusetts Fertilizer Control for 1937, which appear on a preceding 

 page of the bulletin. 



Under the heading "Approximate commercial shortage per ton" is shown the 

 commercial valuation of the deficiencies or tests found below the guarantee 

 after allowance is made for the value of overruns or tests above the guarantee. 



Deficiencies are emphasized by boldface type. 



Mixtures Substantially Complying with the Guarantee. In addition 

 to the analysis of those fertilizers substantially complying with the guarantee, 

 this table includes also those mixtures that are more or less out of balance; 

 that is, having deficiencies in one or more plant food elements, but having 

 overruns which largely offset the value of the deficiencies. 



"Number of samples" indicates the number of samples included in the com- 

 posite which was analyzed. 



Inferior Nitrogen. The presence of inferior forms of organic nitrogen is in- 

 dicated by footnotes. 



Potash Forms. Wherever tests for chlorine showed a sufficient amount 

 present to unite with all of the potash found, the source of the potash is desig- 

 nated as muriate. Wherever insufficient chlorine was found to account for all 

 of the potash, it is evident that form.s of potash other than muriate were used. 

 In such cases, the figures under the sub-heading "As muriate" do not imply 

 necessarily that muriate of potash was actually added to the mixture, but that 

 chlorine was present, probably from impurities in the fertilizer chemicals, in 

 amounts to account for the percentage of potash indicated. The balance of 

 the potash found is listed under the sub-heading "In forms other than muriate" 

 and may be derived from sulfate, nitrate, or carbonate, as the case may be. 



