46.20% lime, and iron oxide 18.37%. It may be 

 used to best advantage on trees which have made 

 strong, nitrogenous growth at the expense of fruit 

 productiDn, and also on peaty soils, poor in lime. 

 Water will not dissolve slag, therefore it should be 

 put in as deeply as possible. 



PHOSPHATE GUANOS. 



The guanos of bats and sea fowl are also valuable 

 sources of phosphoric acid. These materials, how- 

 ever, vary in analysis very much. Each consignment 

 should be analyzed and its price based on its con- 

 tents. The first shipments from a guano deposit are 

 the richest and most valuable, but deteriorate as the 

 deposit is drawn upon. 



CHEAPEST FORM OF PHOSPHORIC ACID. 



The Pennsylvania State Department of Agricul- 

 ture, in Bulletin No. 94, gives the results of 12 years' 

 experiments with phosphates, both acidulated and 

 unacidulated, and seems to show conclusively that 

 the best form in which to purchase phosphoric acid 

 is the untreated bone or rock. This is only on condi- 

 tion that there is plenty of organ icmatter, or humus- 

 forming material, in the soil. 



Under such conditions (with humus in the soil) 

 finely ground rock (unacidulated) gave better results 

 than acidulated rock or bone. This was from the 

 standpoint of both original cost of material and the 



