166 THE AMERICAN NATURALIST. [VoL. XXXII. 
But, carefully as Charpentier had worked out his limited 
theory for the valley of the Rhone, he was not prepared for 
the far grander and more brilliant generalization which Agassiz 
was ready to propose. In an epoch-making address delivered 
at a gathering of naturalists at Neuchatel on July 27, 1837, 
Agassiz propounded the theory that within a geologically 
recent period the whole northern hemisphere, as far down as 
the Mediterranean and Caspian Seas, had been covered with a 
vast sheet of moving glacial ice, maintaining that the glacial 
drift around Neuchatel did not come from the Alps, but from 
the north. 
Brilliant as was Agassiz’s presentation of this theory, it 
astonished rather than convinced his hearers. Among these 
were Von Buch and Elie de Beaumont, two of the most influ- 
ential geologists of the time, both of whom were fairly horrified 
by the seeming extravagance of the theory. Agassiz was then 
but thirty years old, and had strong hopes of being promoted 
to a professorship in some of the larger universities of Europe. 
The indorsement he had received from Cuvier and Humboldt 
amply justified him in such expectations. But whatever the 
prospects had been before, they were scattered to the winds- 
by this address with its unfavorable effect on the minds of the 
influential naturalists who were present. 
Even the warmest admirers of Agassiz would not contend 
that all portions of his theory as first presented were correct. 
He was mistaken in supposing that the ice which covered 
Switzerland had any of it come from the north. Charpentier 
was right in holding that the Alps constituted the centre of 
the whole glacial movement in that part of Europe. But 
Agassiz was correct in his belief that there had been a general 
refrigeration of the northern hemisphere which had profoundly * 
changed both the plants and the animals of the whole region. 
The theory as propounded by Agassiz and afterwards verified 
by him is scarcely less grand, impressive, and revolutionary 
than was that of the Copernican system of astronomy, while 
the work of verifying, defending, and giving currency to the 
theory demanded scarcely less genius than that of its origina- 
tion. But for this task also he was fully competent. 
