EXPERIMENT STATION BULLETINS. 297 



continental glacier accomplished was the grinding up of the underlying rocks 

 into fine particles. According to the foregoing results land which was formed 

 from this glacial material and which was not excessively leached must have 

 been very rich in soluble material. When this land was enriched with nitro- 

 gen, it must have been very productive. 



BAiTB AND EXTENTT OF SOLUBILITY OF UNLJEJA-CHED AND LEACilTED KOCES AND 



MINERALS WHEN THE RATIO OF ROCKS AND MINERALS TO DTSTILLED 



WATER WAS 1 to 0.75 and :\IIXTORB WAIS MAINTAINED AT ROOM TEMPERATURE. 



The subjoined tables contain the results on the rate and extent of solu- 

 bility of various rocks and minerals in the unleached and leached state at 

 75 per cent moisture content and at room temperature. Since there were 

 two series which were conducted at two different times and for a different 

 length of periods, the results of each series are given separately. 



