De Sails sure 89 



De Saussure's theoretical views underwent some modi- 

 fication during the prolonged period occupied by the 

 publication of his work, though they seem never to have 

 advanced much, notwithstanding his constantly increasing 

 experience and the enormous amount of observations 

 amassed by him regarding the rocks of the mountains. 



His first quarto volume appeared in 17 7 9, the second 

 in 1786, the third and fourth in 1796. There was thus 

 an interval of fifteen years during which, with unwearied 

 industry, he continued to traverse the Alps from end to 

 end, and to multiply his notes regarding them. Yet he 

 does not seem ever to have reached any broad conceptions 

 of stratigraphical succession, or of orographical structure. 

 When he came upon strata crumpled and doubled over 

 upon themselves, he thought of crystallization in place as 

 the cause of such irregularities. The idea of subterranean 

 disturbance would sometimes occur to him, but for many 

 years he dismissed it with an expression of his incredulity, 

 remarking that " if the underground fires had been able to 

 upraise and overturn such enormous masses, they would 

 have left some trace of their operation, but that after the 

 most diligent search he had been unable to discover any 

 mineral or stone which might even be suspected to have 

 undergone the action of these fires." * He had thus no 

 conception of any operation of nature, other than that of 

 volcanoes, which could produce great disturbances of the 



text notwithstanding (vol. i. pp. 4, 5). In the same year (1779), De 

 Saussure employs the term Geology in his first volume without any ex- 

 planation or apology, and alludes to the geologist as if he were a well- 

 known species of natural philosopher. (See \\isDiscours Prttiminaire, pp. 

 vii., ix., xiv., xvi.) 



1 Voyages dans les Alpes, vol. iii. (1796) p. 107. 



