IDEAL FERTILIZERS 33 



of phosphoric acid means that six pounds of the actual 

 phosphoric acid are in every hundred pounds of fertilizer, 

 or 120 pounds in every ton. When the grower first looks 

 into this he is likely to reckon up the actual plant food, 

 which on the above tag would amount to 340 pounds 

 and begin to talk about 16GO pounds filler. He will "buy 

 his fertilizer materials and mix them himself before he 

 will pay for so much sand !" But when he begins to 

 figure on these fertilizer materials he finds that to get the 

 120 pounds phosphoric acid he must buy 750 pounds 

 superphosphate, that his sources of ammonia run from 

 6^ to 25 per cent., and that high-grade sulphate of potash 

 carries only 49 per cent, actual plant food. In fact, 

 that the materials necessary to supply this analysis 

 easily make up the 2000 pounds. 



The buyer should note whether the term "Available 

 Phosphoric Acid" is used and not accept a guarantee of 

 "Phosphoric Acid" or "Total Phosphoric Acid" alone un- 

 less the source is of an organic nature, tankage, bone, 

 guano, etc. One exception to this rule would be in the 

 case of Thomas Phosphate Powder, as it is always sold 

 under guarantee of total phosphoric acid, but this mate- 

 rial is seldom used in formulas. After taking this pre- 

 caution, he can be assured he is getting all the plant food 

 represented for "woe be unto" the manufacturer giving 

 short measure. Captain Kose and his inspectors would 

 catch up with him before he got well started in such 

 methods. 



But in the last paragraph there are sometimes pitfalls 



