COMPOUND MANURES 85 



turer, providing that the superphosphate used 

 has been properly made and the dry nitrate of 

 high percentage mixed with a superphosphate, 

 likewise dry, does not give off nitric acid and cause 

 a loss of nitrogen, as was often the case formerly 

 when superphosphate were wet and the nitrates 

 charged with chloride of sodium. The sodium 

 chloride decomposed by the free phosphoric 

 acid caused the bags to burst in transit, for there 

 is no substance which rots bags like free chlorine 

 and fluorine, two elements given off when ni- 

 trate and damp superphosphate are mixed. 



Finally, a manure is made for meadows by 

 mixing kainit with superphosphate or with basic 

 slag. The mixing entails no difficulty. The in- 

 gredients are mixed with a shovel, then the heap 

 is turned over, the product perhaps passed im- 

 mediately to the centrifugal crusher, then to 

 the sifting machine. If the kainit be in blocks or 

 lumps it must be passed to the crusher to reduce 

 it to the desired fineness. 



It has already been remarked that in the 

 case of the superphosphates of ammonia of high 

 strength, the phosphoric acid soluble in water 

 did not retrograde even when the superphos- 

 phate entering into the mixture was of such 

 a nature as to readily lend itself to retrograda- 

 tion. The cause of this phenomenon is of both a 

 physical and ohemical nature. The more the 

 superphosphate is distended by ballast, which 

 is here sulphate of ammonia, the more distant 



