A HISTORY OF SCIENCE 



But the implications of the theory of glaciers ex- 

 tend, so Agassi z has come to believe, far beyond the 

 Alps. If the Alps had been covered with an ice sheet, 

 so had many other regions of the northern hemisphere. 

 Casting abroad for evidences of glacial action, Agassiz 

 found them everywhere in the form of transported 

 erratics, scratched and polished outcropping rocks, 

 and moraine-like deposits. Finally, he became con- 

 vinced that the ice sheet that covered the Alps had 

 spread over the whole of the higher latitudes of the 

 northern hemisphere, forming an ice cap over the globe. 

 Thus the common -sense induction of the chamois- 

 hunter blossomed in the mind of Agassiz into the con- 

 ception of a universal ice age. 



In 1837 Agassiz had introduced his theory to the 

 world, in a paper read at Neuchatel, and three years 

 later he published his famous Etudes sur les Glaciers, 

 from which we have just quoted. Never did idea make 

 a more profound disturbance in the scientific world. 

 Von Buch treated it with alternate ridicule, contempt, 

 and rage ; Murchison opposed it with customary vigor ; 

 even Lyell, whose most remarkable mental endow- 

 ment was an unfailing receptiveness to new truths, 

 could not at once discard his iceberg theory in favor 

 of the new claimant. Dr. Buckland, however, after 

 Agassiz had shown him evidence of former glacial ac- 

 tion in his own Scotland, became a convert the more 

 readily, perhaps, as it seemed to him to oppose the uni- 

 formitarian idea. Gradually others fell in line, and 

 after the usual imbittered controversy and the inev- 

 itable full generation of probation, the idea of an ice 

 age took its place among the accepted tenets of geol- 



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