INTRODUCTION. 55 



strange that De Saussure should have provided us with a 

 minute description of the rounded, hummocky terrains in the 

 Alps, which he termed " roches moutonnees," and should even 

 have observed the scratches upon these rocks, and yet have 

 failed to associate such phenomena at lower Alpine levels with 

 anything that he had observed in the higher altitudes. On 

 the other hand, realising as we do to day the extreme com- 

 plexity of Alpine stratigraphy, it is readily comprehensible why 

 in spite of the extraordinary number of his observations, De 

 Saussure could not construct from them any definite chrono- 

 logical succession of the rock-strata in the Alps. He certainly 

 differentiated the secondary Alpine rocks from the primitive 

 crystalline masses in the central chain, and distinguished the 

 deposits in the plain of Piedmont as Tertiary. 



In his conceptions of the origin of granite, schists, and 

 igneous dykes De Saussure followed Neptunistic doctrines. 

 Finally, after much hesitation, he allowed that the sedimentary 

 series had been deposited horizontally and only subsequently 

 elevated and tilted, but he would not agree to the Volcanistic 

 teaching that volcanic force had upheaved the rocks. Looking 

 back on De Saussure's geological writings, it might seem that 

 from their lack of broad generalisations they had failed to 

 exert a direct influence upon the progress of Alpine geology. 

 Yet their faithful observations have made them reliable books 

 of reference for all Swiss geologists to the present day. De 

 Saussure's love of truth and his passion for nature, combined 

 with the extreme modesty of his attitude towards the science 

 of the mountains, have made him an ideal personality in the 

 annals of Alpine geology. 



Endless in his energy, insatiable in his desire to accom- 

 plish, De Saussure, at the conclusion of his life's labours, writes 

 that he has found nothing constant in the Alps except their 

 infinite variety. With a feeling of sadness he admits the 

 futility of all his efforts to wrest the eternal truths of nature 

 from the majestic peaks of his native land. Then it was that 

 he wrote his charming book of Instructions to Young Geologists. 

 He impresses upon them above all to keep their minds free 

 from bias in favour of one scientific opinion or another, to 

 make it their chief aim to observe with the greatest deliberation 

 and detail, to omit nothing as unimportant, and at the same 

 time not to lose sight of the possible value of all facts in 

 establishing the fundamental principles of the science. 



