344 M. Escher de la Linth 07i certain Phenomena 



comparative anatomy, zoology, or botany, without an ade- 

 quate acquaintance with the principles and known laws of the 

 science essentially involved in the question. Now, unless our 

 conclusions will bear the test of the most strict examination 

 by those who are acknowledged authorities in the particular 

 science, it is obvious that we cannot make any secure pro- 

 gress. The study of Geology, more perhaps than that of any 

 other branch of natural science, has a tendency to create a 

 disposition to theorize ; this disposition, however, if kept with- 

 in due bounds, is rather to be encouraged than repressed, for 

 it has often proved a stimulus to accurate observation ; and 

 to arrive at a knowledge of a true theory of the earth, is, in 

 truth, the great aim of our inquiries. But we must carefully 

 guard against the error which the earlier geologists too fre- 

 quently fell into, of quitting the sober path of inductive phi- 

 losophy, and wandering into the regions of imagination. We 

 must indulge in no theory that is not in accordance with laws 

 of nature of which we have had experience, or which may be 

 fairly inferred from that experience, although the operations 

 we seek to explain may have been on a greater scale than 

 any of which we have certain knowledge. The cautious and 

 accurate Playfair was wont to inculcate upon those who 

 studied in the school of Hutton, the warning of the noble 

 aphorism with which Bacon opens his great work, the *' No- 

 vum Organum,'' — an aphorism which every geologist will do 

 well to bear in mind when he ventures to theorize on causes: — 

 " HomOf naturw minister et inter pres^ tantum facit et intelligit, 

 quantum^ de naturw ordine, re vel mente observaverit ; nee am- 

 pUus scit, aut potest.^^ 



On certain Phenomena presented by the Glaciers of Switzer- 

 land.^ By M. Escher de la Lintii. (With a Plate.) 



I have just read, with much interest, the memoir of M. 

 Durocher on the erratic phenomena of Scandinavia, and am 

 glad to perceive that M. Durocher is of opinion, that the 

 agent which has produced furrows on the surface of Scandi- 



* In this article there is some obscurity, probably owing to a bad manuscript. 



