GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 135 



If, however, yellowish sediment is distributed through the ice in proper propor- 

 tions the case is identical with that discussed for water, and the ice assumes a 

 greenish cast. In the case of the solid ice the sediment can not be assorted and 

 evenly distributed as in the case of water and hence only greenish patches and 

 streaks occur, just where conditions are favorable. It has not seemed appropriate 

 to any one to apply the names "emerald," or "turquoise," to a glacier while 

 "sapphire" would not be very distinctive. By applying the principles here 

 set forth we may account for the coloration of glaciers, the lakes in their neigh- 

 borhood; the gorgeous pools of blue and green water in the Yellowstone Park 

 and similar regions, the blue color of the ocean and the seas, the green and final 

 yellow strip as we approach the shore and such phenomena as the blue and green 

 grottoes of the island of Capri. No one has yet satisfactorily explained how a 

 considerable body of pure water may appear limpid. 



THE END. 



