1865.] CHEMISTRY OF NATURAL WATERS. 21 



The above classification, although adopted originally for the 

 convenient description of the mineral waters of Canada, will, it is 

 thought, be found to embrace all known classes of natural waters, 

 with the exception of those included under E, and of some waters 

 from volcanic sources holding muriatic acid. These may consti- 

 tute two additional classes. In the first three of the classes above 

 described, chlorids predominate ; in the fourth, carbonates ; and in 

 the fifth and sixth, sulphates. The waters of the first, second, 

 and sixth classes are neutral ; those of the third and fourth, alka- 

 line ; and those of the fifth, acid. 



The results of the chemical analysis of various waters of these 

 classes, it is proposed to give in the second part of this paper. — 

 From Slllimans American Journal of Science, No. 116, 1865. 



ON THE RELATIVE POWERS OF GLACIERS AND 

 FLOATING ICEBERGS 



IN MODIFYING THE SURFACE OF THE EARTH. 



By Sir Roderick I. Murchison. 



Before I enter on the consideration of the new theory of the 

 power of moving ice, let us take a review of the progress recently 

 made in pointing out the extent to which ancient glaciers and 

 their moraines have ranged within or on the flanks of the Alps. 

 In the northern portions of the chain these phenomena long ago 

 attracted the attention of some admirable observers. Originating: 

 with Venetz and Charpentier, the true active powers of glaciers 

 were defined by Rendu, Agassiz, and Forbes, and subsequently by 

 other explorers. In short, no doubt any longer obtains, that 

 such was the powerful agency of the grand ancient glaciers, that 

 blocks of crystalline rock were transported by them from the 

 central Alps of Mont Blanc to the slopes of the Jura Mountains. 

 When, however, we begin to seek for satisfactory explanations of 

 the method of transport of these huge erratics, geologists (who are 

 only geographers of another order) entertained different opinions. 

 For my own part, I have had strong doubts as to whether the great 

 blocks derived from Mont Blanc, and which lie on the slopes of the 

 Jura, were ever borne thither by a vast solid glacier which advanced 

 from the Lake of Geneva over the Cantons of Vaucl and Neufchatel. 

 Whilst fully believing in the great power of glaciers and their 



