GO M. Cliaqienticr on (he Erratic Vlicnomcna of the North. 



on the fact, that they find at the foot of the glacier, among 

 the debris brought down by it, fragments of rock evidently 

 detached from that mountain. Starting with this idea, they 

 believe that the hypothesis in question, applied to the erratic 

 phenomenon of the north, obliges them to admit that the ice 

 which formerly covered the countries where the erratic debris 

 are met with, that is to say, the immense extent included be- 

 tween the north of Scandinavia, Moscow, and Lcipsic, came 

 wholly from the mountains of Norway or of Spitzbergen, or 

 of some part of the Polar regions. But such a supposition is 

 quite as inadmissible as that which would attribute to the 

 source of the Rhone all the water which that river contains 

 when it falls into the lake, and that because there had been 

 recognised among the wood it transports, trees evidently de- 

 rived from near its source. The absurdity of this supposition, 

 though based on a fact which is very true, is at once apparent. 

 It is the same thing with glaciers ; for the snow which has 

 given rise to the formation of the ice, does not all come from 

 the mountains where they had their origin ; on the contrary, 

 the ice derived from the hauts-ntves (Essai, § 3 and § 10) 

 only forms a part, sometimes a very small one, of their en- 

 tire mass. In fact, as the ice of a glacier is chiefly produced 

 by thfe congelation of the water which, as often under the 

 form of rain as of snow, has fallen on it and been absorbed by 

 it, it is evident that the more surface a glacier presents, the 

 more the portion of ice having that origin ought to be consi- 

 derable, compared with that which has really descended from 

 the mountain. There is therefore no need of supposing that 

 all the ice of the diluvian glacier of the north came from one 

 single point ; on the contrary, that vast glacier would be con- 

 stantly increased by the rain and the snow falling directly 

 upon it, and its increase must have gone on augmenting in 

 proportion as it acquired a larger surface. 



AVe must no longer persuade ourselves that the change in 

 the snows of the north only commenced its operations at one 

 single locality, more or less limited. This change must have 

 taken place simidtaneously in the whole region where the 

 summer temperature was not sufficiently high to cause the 

 entire disappearance of the winter snows. Such a state of the 



