CHEMISTRY OF FERTILIZERS 9 



in fertilizers, but chemists use this form of ex- 

 pressing the results of analyses as a convenient 

 standard for reference. Fertilizers generally con- 

 tain potash in such forms as sulphate of potash, 

 muriate of potash, or carbonate of potash. In- 

 stead of stating the amount of sulphate, muriate, 

 or carbonate of potash in a fertilizer, its equivalent 

 amount is stated only in the form of actual potash 

 in giving the results of analyses. 



(B) Potash actual is simply another name for 

 potash, as distinct from sulphate, muriate, etc. 



(C) Potash S. (or Sul.) means sulphate of 

 potash. This is quite often used by manufac- 

 turers in giving guarantees. 



(D) Potash soluble represents the amount of 

 potash that dissolves in water and is available 

 for the use of plants. The different forms of 

 potash commonly used in fertilizers are readily 

 soluble in water, otherwise they would not be 

 available for the use of plant life. 



(E) Potash as sulphate means simply sulphate 

 of potash. 



(F) Potash equal (or equivalent to sulphate 

 of potash) is an expression which means simply 

 sulphate of potash. 



(G) Sulphate of potash signifies that this com- 

 pound is actually present in the fertilizer, and 

 that there is no muriate of potash present. 



(H) Potassium oxide means the same as potash, 

 or actual potash. 



The phosphoric acid in raw materials such as 



