292 In and Around the Morteratsch Glacier : 



liberated by the melting of the ice in which it was confined, 

 seems by preference to remain adherent to the ice, partly as 

 a fine semi-transparent layer and partly as small patches, 

 perhaps of the size of a bean. If the surface of the ice be 

 rubbed over with the hand it becomes completely obscured 

 with the mud, and it costs some trouble to get it clean enough 

 to be able to take a photograph through it. The mud is 

 undoubtedly the product of the kaolinisation of the felspathic 

 rocks of the neighbourhood, and the sand is some of the 

 quartz which has been liberated by this purely chemical 

 process of disintegration, which is accompanied by the pro- 

 duction of carbonates and of other slightly soluble salts 1 . 



It is never questioned that the water of a stream which 

 in time of flood may have passed from the clouds over the 

 soil into the stream bed in a few hours, has taken into solution 

 some mineral matter, and river water is therefore always 

 accepted as being prima facie impure. No one who has been 

 placed in the situation of having to melt snow on the moun- 

 tains to quench his thirst is likely to forget his dissatisfaction 

 on discovering that the water produced was muddy. The 

 sand and dust blown on to the surfaces of snow and neve get 

 completely mixed up with the mass which, throughout a large 

 part of the year, is in a constant state of alternate melting 

 and freezing, and the mineral matter which thus becomes 

 incorporated with the snow, neve and ice persists in this state 

 at any rate for many years. The certainty that some of it 

 will pass into solution and influence the melting temperature 

 of ice in contact with it cannot be contested. 



Usefulness of the Artificial Grottos, which are met with in all 

 frequented Glaciers, for the Study of Glacier-Ice in its 

 Primary State. 



The motive which drove me in the first instance to visit 

 the Swiss glaciers was to study the glacier-ice rather than 

 the glaciers themselves. For this purpose it was necessary 

 to have entry to the inner mass of the glacier. At first 



1 See Bischof, Chetnische und Physikalische Geologic, Bd. i. Rap. i. , vi. 



