202 On the Physical Geography of the Alps, 



weichen) of the masses. We ought here to observe, that the 

 study of the valley-formation of the Alps can only be well 

 followed out, in proportion as the general position of the 

 strata approaches the perpendicular. For the strata often 

 preserve over large tracts the same direction and dip, and 

 are frequently cut through by a series of valleys without 

 suffering any change. One might expect that in the great 

 basin-like depressions, the inclination of the strata would be 

 in some degree altered. Still we must consider that the up- 

 rise or tilting of the strata is unusually steep in the Alps : a 

 partial withdrawal therefore, may happen without any very 

 striking disturbance of the inclination and the succession of 

 strata, and is far more possible than under the conditions of 

 horizontal stratification. Sometimes only are we led to 

 notice very striking disturbance of the stratification, particu- 

 larly in the limestone Alps, and these indeed, where the 

 greatest irregularity of the valley bottoms has been effected 

 by the deep depressions that even yet are occupied by the 

 Alpine lakes. These are confined chiefly to the north and 

 south districts, and are altogether wanting in the central 

 parts where the crystalline slates abound and where the 

 elevation is most regular.*" 



2. Origin and Formation of Springs. 

 Mr A. Schlagintweit, in this section of the work, gives a 

 detailed and interesting account of his investigations and 

 observations on the Origin and Formation of the Springs in 

 the Alps. The general results are given thus : — 1. In em- 

 ploying springs for the determination of the local tempera- 

 tures of the earth, it is indispensable that, in arriving at 

 comparable results, we direct our attention to the geological 

 formations and local conditions, on which the nature of the 

 origin of springs is necessarily dependent. 2. The origin of 

 springs is not only connected with the mode of stratification, 

 but also, and that most intimately, with the general charac- 

 ter of the rock formation. 3. The fissures and porosity of 

 limestone give rise to important diff'erences in the conditions 

 attendant on this rock and on crystalline slates. In limestone, 

 the springs are seldom, but copious, and, coming through 



* Journal of the Geological Society, February 1861. 



