Bulletin 92, Bureau of Chemistry, U. S. Department of Agriculture. 



PLATE IV. 



FIG. 1. SAME POWDER AS SHOWN IN PLATE III, FIG. 2, BUT STAINED WITH 



METHYLENE BLUE. 



sf&j 



.v 





ib*V*** 



FIG. 2. WET GROUND ORTHOCLASE POWDER, REMAINING IN SUSPENSION IN WATER 



AFTER SEVERAL DAYS, DRIED AND LIGHTLY PULVERIZED 



(ENLARGED 25 DIAMETERS). 



