338 On the Colour oj the Water of Glaciers. 



tions at the terminal vault of the glacier of the Aar, in 1845 

 and 1846, for experiments in gauging. 



In fine weather, when viewed from a distance in a mass, 

 it has a grey, tarnished, and opaque appearance ; it holds a 

 great quantity of mineral particles in suspension. During 

 rain, the grey changes to ochre-yellow ; when examined in a 

 flask or glass, the diflerence of hue partly disappears. All 

 this is explained if we take the origin of this water into 

 consideration. It is derived from four different sources : 1st, 

 from the ice ; 2dly, from the superior neve ; 3d, from rain ; 

 4thly, from atmospheric condensation, (the spring-water 

 which may rise under a glacier is insignificant). Before 

 reaching its terminal point, it performs an important part in 

 the economy of the glacier. By means of canals and capil- 

 lary fissures, it circulates throughout the entire mass, and 

 carries along with it the bodies it encounters in its passage. 



Independent of the mineral particles whose origin is 

 known, it likewise holds in suspension a great quantity of 

 organic fragments, both vegetable and animal. The Mers 

 de Glace of the high alpine regions are inhabited by a multi- 

 tude of organised beings, as yet little known. Thus MM. 

 Oh. Vogt and Bassnitz, who have entered upon investiga- 

 tions (partly unpublished) relating to the red snow, which is 

 very abundant on glaciers, have discovered under the micro- 

 scope, and 1 can myself verify the fact, that besides the 

 sporules of Protococcus which constitute the red snow, the 

 waters of glaciers contained a very great variety of frag- 

 ments of hitherto undetermined cryptogamous vegetables. 

 I have no doubt that further researches will enable us 

 at a subsequent period to introduce a glaciary flora into 

 science. 



With regard to animal organisms, M. Desor was the first 

 to make known the existence of glacier fleas {Desoria gla- 

 cialis.) They are found over the whole extent of the sur- 

 face. On the glacier of the Aar, we have only to lift the 

 first stone from the median moraine to discover myriads. 

 These small insects are so numerous in their icy dwelling, 

 that it acquires a blackish hue from them. They are unable 



