86 MANUFACTURE OF FERTILIZING MATERIALS 



the particles are from one another which pre 

 serves their condition. From a chemical point 

 of view, sulphate of ammonia possesses the prop- 

 erty of hindering the basic sesquioxides from 

 precipitating themselves, but it is clear that a 

 retrograded superphosphate cannot be improved 

 by mixture with sulphate of ammonia. 



