HUMBOLDTS VIEWS ON ICE-PERIOD. 345 



boundless activity, of your beautiful intellect- 

 ual life, increases with every year. This ad- 

 miration for your work and your bold excur- 

 sions is based upon the most careful reading 

 of all the views and investigations, for which 

 I have to thank you. This very week I have 

 read with great satisfaction your truly philo- 

 sophical address, and your long treatise in 

 Cotta's fourth " Jahresschrift." Even L. von 

 Buch confessed that the first half of your 

 treatise, the living presentation of the succes- 

 sion of organized beings, was full of truth, 

 sagacity, and novelty. 



1 in no way reproach you, my dear friend, 

 for the urgent desire expressed in all your 

 letters, that your oldest friends should accept 

 your comprehensive geological view of your 

 ice-period. It is very noble and natural to 

 wish that what has impressed us as true 

 should also be recognized by those we love. 

 ... I believe I have read and compared all 

 that has been written for and against the ice- 

 period, and also upon the transportation of 

 boulders, whether pushed along or carried by 

 floods or gliding over slopes. My own opin- 

 ion, as you know, can have no weight or au- 

 thority, since I have not myself seen the 

 most decisive points. Indeed I am, perhaps 



