375 



occurrence on the lower slopes of the mountains, and they are 

 often intersected by brooks. If the tensions of carbonic acid 

 in the latter are examined, at the points of their entering and 

 leaving a bog, it will be found that a considerable rise is 

 caused by the passage: 



The rise may partly be due to the respiration of the roots 

 among which the water flows, and partly to their secretion of 

 acid which will combine with the alkali in the water and set 

 free the carbonic acid. 



At the beginning of this chapter I stated, that almost all 

 the freshwaters in Disko are surface-waters and gave the reason 

 for it, viz. That the earth at a depth of less than 1 m. is frozen 

 all the year round. The sheet of ice which thus separates the 

 surface from the deeper strata, where the temperature is again 

 positive, is certainly very thick, and it is absolutely inconceivable 

 that water from the surface should find ils way through it. 



In some places, nevertheless, water rises from the depth 

 and forms the so-called «Unartut» or hot springs. The word 

 «hot spring» must, however, not be taken too literally, for the 

 temperature of some of them is not more than 2 — 6°^), but 

 they are distinguished by their flowing continuously during the 

 winter, when all other streams are dry or frozen. 



I have examined a spring on the south-coast of the Disko- 



') The hottest spring, known in Disko, was found by Steenstrüp in 

 Mellemfjord on the west-coast of the Island. Its temperature was 18.8° 

 (Medd. от Grønland, Hefte 24 p. 287). 



