54 (leology, as illustrated by Chemistry and Physics. 



that which is indeed not the least of having, more than any 

 other geologist directed attention to the difficulties involved 

 in the explanation of geological phenomena, by the hypothesis 

 of plutonic metamorphism,* has observed, that at Mettenberg, 

 near Grindelwald, limestone strata of scarcely more than an 

 inch in thickness, surrounded on both sides by gneiss, neither 

 lose their gray colour, nor their uncrystalline sedimentary 

 character, and that distinctly preserved fossil remains (Be- 

 lemnites and Ammonites), were situated almost at the sur- 

 faces of contact. 



Should not this single fact have been sufficient to have 

 shewn that this gneiss could not possibly have been formed 

 by plutonic metamorphism, without the thin strata of lime- 

 stone being at the same time altered, their colour and the 

 fossil remains destroyed? Nevertheless, the more such facts 

 are accumulated, the more do the plutonic notions of meta- 

 morphosis reappear again in a new form. 



Such extravagancies in empirical sciences are but little 

 adapted to inspire respect for the investigation of nature in 

 the public mind. Would it not be more creditable for 

 scientific men at once to admit their inability to explain com- 

 plicated phenomena, than to contrive hypotheses which stand 

 in contradiction to all sound reasoning? What kind of idea 

 would be formed of the geologists of the nineteenth century, 

 should these pages be read a century hence, and it should be 

 seen that views such as that of plutonic metamorphism 

 were maintained, and cost so much trouble to disprove ? 



That metamorphic processes go on uninterruptedly, as 

 well in the inorganic as the organic kingdom, is an indisput- 

 able fact. If these cannot be explained by the action of heat, 

 other methods must be adopted. I must now leave it to a 

 future occasion to point out how far it has been possible to 

 discover such. 



* Loc. cit., pp. 135, 158. 



