302 Bureau of Farmers' Institutes. 



Before taking up a consideration of the mathematical details, 

 we will make a brief explanation of the different terms used in 

 expressing fertilizer guarantees and analyses, because an accurate 

 knowledge of such terms is important, especially in making com- 

 mercial valuations and in planning formulas. 



We shall, therefore, consider under the general head given 

 above the following topics: 



1. Explanation of terms used in stating guarantee analyses of 

 fertilizers. 



2. Total constituents of fertilizers. 



3. Commercial valuation of fertilizers. 



4. How to calculate amounts of materials to be used in making 

 home-made fertilizers. 



1. Explanation op Terms Used in Statino Guarantee Analy- 

 ses of Fertilizers. 



In examining the guarantee analyses of different manufactur- 

 ers, we find much variation in the terms used. Sxmie forms are 

 simple, stating only the most essential points, while others are 

 complicated and confusing to the average farmer. We purpose 

 here briefly to explain all the different forms which are apt to be 

 met. The following list contains most of the terms used in stat- 

 ing manufacturers' guarantee analyses: 



Nitrogen is expressed as 



(a) Nitrogen, (b) ammonia, (c) nitrogen equal (or equivalent) 

 to ammonia. 



Phosphoric Acid is expressed as 



(a) Phosphoric acid, (b) soluble phosphoric acid, (c) reverted 

 phosphoric acid, (d) precipitated phosphoric acid, (e) avail- 

 able phosphoric acid, (f) soluble and available phosphoric 

 acid, (g) insoluble phosphoric acid, (h) total phosphoric 

 acid, (i) phosphoric acid equal (or equivalent) to bone 

 phosphate of lime. 



Potash is expressed as 



(a) Potash, (b) potash (actual), (c) potash s. (or sul.), (d) pot- 

 ash {soluble), (e) potash as sulphate, (f) potash equal (or 

 equivalent) to sulphate of potash, (</) sulphate of potash, 

 (li) potassium oxide. 



