VI MOUNTAINS 233 



well as the rivers issuing from them, are a 

 beautiful rich blue. 



"Is it not probable that this action of 

 finely-divided matter may have some influ- 

 ence on the colour of some of the Swiss lakes 

 — as that of Geneva for example ? This lake 

 is simply an expansion of the river Rhone, 

 which rushes from the end of the Rhone 

 glacier, as the Arveiron does from the end of 

 the Mer de Glace. Numerous other streams 

 join the Rhone right and left during its 

 downward course; and these feeders, being 

 almost wholly derived from glaciers, join the 

 Rhone charged with the finer matter which 

 these in their motion have ground from the 

 rocks over which they have passed. But the 

 glaciers must grind the mass beneath them 

 to particles of all sizes, and I cannot help 

 thinking that the finest of them must remain 

 suspended in the lake throughout its entire 

 length. Faraday has shown that a precipi- 

 tate of gold may require months to sink to 

 the bottom of a bottle not more than five 

 inches high, and in all probability it would 

 require ages of calm subsidence to bring all 



