The Composition and Use of Fertilizers. 305 



entry for the sole purpose of misleading the farmer into thinking 

 that the phosphoric acid has come from hone and also because, 

 stated in this form, there appears to he twice as much phosphoric 

 acid. 



Potash. 



(a) Potash, as used in connection with fertilizers, always means 

 a compound containing potassium and oxygen, known as potas- 

 sium oxide. Potash or potassium oxide is never found as such 

 in fertilizers, but chemists use this form of expressing the results 

 of analysis as a convenient standard for reference. Fertilizers 

 generally contain potash in such forms as sulphate of potash, 

 muriate of potash or carbonate of potash. Instead of stating the 

 amount of sulphate, muriate or carbonate of potash present in a 

 fertilizer, its equivalent amount is stated only in the form of 

 potash in giving the results of analysis. 



(b) Potash Actual is simply another expression for potash, as 

 distinct from the sulphate, muriate, etc. 



(c) Potash S. {or Sid.) means sulphate of potash. This is 

 quite often used by manufacturers in giving guarantees. It is 

 very misleading and, when used, is evidently employed for the 

 purpose of making purchasers think that it is actual potash. One 

 pound of potash is equivalent to 1.85 pounds of sulphate of pot- 

 ash; and so, in stating a guarantee as sulphate, the manufacturer 

 makes it appear that his goods contain more potash than they 

 really do. 



(d) Potash Soluble represents the amount of potash that dis- 

 solves in water and is available for the use of the plants. The 

 different forms of potash commonly used in fertilizers are readily 

 soluble in water. 



(e) Potash as Sulphate means simply sulphate of potash. 

 (/) Potash equal {or equivalent) to Sulphate of Potash is an 



expression which means simply sulphate of potash. When the 

 potash is present as muriate, this expression should never be used. 



{g) Sulphate of Potash signifies, or should signify, that this 

 compound is actually present in the fertilizer and there is no 

 muriate of potash present. 



(h) Potassium Oxide means the same as potash or actual potash. 



Advice Regarding Guarantee Analyses. — When a farmer 

 purchases either a mixed fertilizer or separate fertilizing mate- 

 rials, he should purchase only under a guarantee of specified 

 20 



