264 SALMONIA. 



upon snows, yet this is a rare occurrence; 

 and red snow, which is occasioned by it, is 

 an extraordinary and not a common pheno- 

 menon towards the pole, and on the highest 

 mountains of the globe. Having examined 

 the water formed from melted snows on gla- 

 ciers in different parts of the Alps, and 

 having always found it of the same quality, 

 I shall consider it as pure water, and describe 

 its characters. Its colour, when it has any 

 depth, or when a mass of it is seen through, 

 is bright blue ; and, according to its greater 

 or less depth of substance, it has more or 

 less of this colour: as its insipidity and its 

 other physical qualities are not at this mo- 

 ment objects of your inquiry, I shall not 

 dwell upon them. In general in examining 

 lakes and masses of water in high mountains, 

 their colour is of the same bright azure. 

 And Captain Parry states, that the water on 

 the Polar ice has the same beautiful tint. 

 When vegetables grow in lakes, the colour 

 becomes nearer sea green, and as the quan- 

 tity of impregnation from their decay in- 

 creases greener, yellowish green, and at 



