n8 POPULAR SCIENCE MONTHLY. 



a lodge on the shore of the lake, where Desor and Yogt were in- 

 stalled to carry on the investigations. Yogt composed here the 

 anatomical part of Desor's work on Fossil Fishes, the Fishes of the 

 Old Bed Sandstone, and the German edition of Studies of Glaciers. 



The controversy concerning glacial action was at its height. A 

 theory had been proposed of an immense glacier having once occu- 

 pied the Ehone Valley above Martigny, but Agassiz was still doubt- 

 ful about it. He, with Desor, had visited the principal glacial 

 fields of the Alps, and conceived a plan for studying a glacier con- 

 tinuously. In 1839 a party of about a dozen students, of whom 

 Agassiz, Desor, Yogt, and Pourtales are best known to Americans, 

 with guides and porters, established themselves by the lower glacier 

 of the Aar, where they could watch its inner life. A suitable camp- 

 ing place was found by the side of an immense bowlder, and a lodge 

 was instituted and given the name of the Hotel des Neuchatelois. 

 The hotel was much visited during the four years, the students occu- 

 pied it by guests, many of whom became illustrious in science. 

 Vogt's first book, Ira Gebirg und auf den Gletschem, embodying his 

 experiences there, was published in 1842. 



The new glacial theory was still bitterly opposed, and by no one 

 with more vigor than Leopold von Buch. It fell to Yogt to defend 

 it before the German scientific meeting at Erlangen in 1840, and 

 then at Mayence, both times in von Buch's presence. His exposi- 

 tions were interrupted by frequent objections from von Buch, who 

 replied with all his force. Yogt, paying no attention to invectives 

 and sarcasms of his antagonist, simply exposed the insufficiency of 

 his arguments, and concluded with a protest against the road to free 

 inquiry being barred by the mischievous principle of authority in 

 science. He won the day. Shortly after this Yogt and Agassiz 

 differed on a question concerning the award of credit for discoveries 

 and publications and separated. 



Yogt spent three years in Paris, working busily and producing 

 many zoological and biological memoirs; published his Text-book 

 of Geology and Petrifactions, and figured prominently in the forma- 

 tion of the Society of German Physicians, which has become a very 

 important body. In the text-book he expressed doubts concerning 

 the theory of a fluid nucleus within the earth, which everybody held 

 then. Vogt's fame reached the general public through his Physio- 

 logische Brief e, a book which brought the science within the com- 

 prehension of the ordinary reader, while it was still welcome to the 

 professional man. It treated the subject of generation with a 

 plainness that had not been ventured upon in any other popular 

 work; and it attacked the doctrine of the survival of the soul, affirm- 

 ing, in effect, that all the properties designated as mental activity 



