() DOMAIN VII. COMPOSITE. 



of rocks, arising from local relations, must 

 always be regarded as empyrical, and will 

 often prove wholly erroneous. That great 

 observer, Saussure, found, in the ample 

 scene of the Alps, that he was farther re- 

 moved from the formation of a theory, 

 after the sedulous labour of forty years, 

 than at the beginning ; that instead of any 

 regular plan or order, he found perpetual 

 contradictions, in the assemblage and co- 

 alescence of substances, that seemed to be 

 wholly remote and dissimilar. " It may 

 well be affirmed/' says he, " that there is 

 nothing certain in the Alps, but their va- 

 riety. .... Sometimes the skirts are cal- 

 careous, sometimes magnesian. The cen- 

 tres and highest summits are here of mass- 

 ive granite, there of a calcareous mica slate; 

 sometimes of magnesian stones, sometimes 

 of gneiss : if the beds be considered, here 

 they are vertical, there horizontal; here 

 their inclination follows the slope of the 

 mountain, there quite the contrary/'* We 

 may add, from more recent observations, 



* 2301. 



