xiv INTRODUCTION. 



appreciate the life of an extraordinary man, a few let- 

 ters and quotations in French, scattered through the 

 work, will present no difficulties to its readers. On the 

 contrary, they will be a sort of stimulant and a relish, 

 both scientifically and from a literary point of view. 



For the same reason, an address the most impor- 

 tant of the many delivered by Agassiz - - has been 

 reproduced in the original. It is his celebrated dis- 

 course of 1837, on a " Great Ice-age." 



During the period from his twenty-third to his fortieth 

 year, Agassiz wrote many letters in German, mainly of 

 a private nature, addressed to members of his German 

 family or to a few most intimate friends. Almost all 

 his scientific letters were directed to his old professor 

 at Heidelberg, H. G. Bronn, and have been published 

 in the " Neues Jahrbuch fiir Mineralogie, Geologic und 

 Petrefaktenkunde." Although he was a perfect master 

 of German, speaking and writing it like a native of 

 Heidelberg or Munich, he never published important 

 papers in that language, only a few pamphlets, the 

 principal one being his reply to Karl Schimper's claims, 

 4 pp. 4to. 



Agassiz's remarkable personality cannot be properly 

 understood without taking into account the strength of 

 his French nature. A Franco-Swiss he was born ; and 

 a Franco-Swiss he remained all his life, notwithstanding 

 his American naturalization and his great admiration 

 of the New World in general, and of the United States 

 in particular. 



