288 On the Physical Geography of the Alps. 



plates, and woodcuts. A rapid perusal of part of this work, 

 of which one copy only has reached Edinburgh, enables us 

 to submit to our readers a few observations on it, and also 

 some illustrative extracts. 



This work is divided into four principal sections, consisting 

 of researches, first, on the glaciers ; second^ on the geology ; 

 third, on the meteorology; smd fourth, on the botanical geo- 

 graphy of the Alps. 



I. — Glaciers. 



The natural history of the glaciers has, since the time of 

 Saussure, engaged the particular attention of naturalists, of 

 whom the most distinguished are Agassiz, Charpentier, 

 Professor J. D. Forbes, and the Schlagintweits. These last- 

 mentioned naturalists enumerate in their work all that was 

 previously known in regard to glaciers, and many interesting 

 circumstances not noticed by others. We have only leisure 

 at present to remark in regard to glaciers, that the most im- 

 portant discussion refers to the nature of their motion. Our 

 authors consider it due to the movement of the granules of 

 ice, which they say form the chief bulk of the glacier. This 

 explanation appears to us to be the theory of Professor J. 

 D. Forbes, our authors substituting coarse granules of ice for 

 the theoretical molecules of the viscous mass. But the fact 

 announced by M. Person at p. 172 of the present volume 

 of this Journal should be explained more fully, and formally 

 brought into play in discussing this curious subject. 



Section II. — Geology of the Alps. 

 1. Origin of Valleys. 

 In section second, which treats of the geology of the Alps, 

 we have many interesting remarks by Mr Adolph Schlagin- 

 tweit on the formation of valleys and the forms of the 

 mountain-chains and mountain-groups of the Alps. Valleys 

 it is remarked by him have been sometimes regarded as almost 

 exclusively the effect of violent floods and torrents, but in 

 later times causes more complicated and connected with the 

 geology of the district have been sought for. Bouguet and 

 BufFon believed that in most valleys the salient angles of one 

 side corresponded with the re-entrant angles of the opposite 

 declivity of the valley, and that all valleys have their origin 



