vi Mr. Henry Clifton Sorby 279 



by means of the microscope, it was possible to discover 

 the minute structure and composition of rocks, and to learn 

 much regarding their mode of origin. He took us, as it 

 were, into the depths of a volcanic focus, and revealed the 

 manner in which lavas acquire their characters. He 

 carried us still deeper into the terrestrial crust, and laid 

 open the secrets of those profound abysses in which granitic 

 rocks have been prepared. His methods were so simple, 

 and his deductions so startling, that they did not instantly 

 carry conviction to the minds of geologists, more par- 

 ticularly to those of his own countrymen. The reproach 

 that it was impossible to look at a mountain through a 

 microscope was brought forward in opposition to the new 

 departure which he advocated. Well did he reply by 

 anticipation to this objection. "Some geologists, only 

 accustomed to examine large masses in the field, may 

 perhaps be disposed to question the value of the facts I 

 have described, and to think the objects so minute as to 

 be quite beneath their notice, and that all attempts at 

 accurate calculations from such small data are quite 

 inadmissible. What other science, however, has prospered 

 by adopting such a creed? What physiologist would 

 think of ignoring all the invaluable discoveries that 

 have been made in his science with the microscope merely 

 because the objects are minute ? . . . With such striking 

 examples before us, shall we physical geologists maintain 

 that only rough and imperfect methods of research are 

 applicable to our own science ? Against such an opinion 

 I certainly must protest ; and I argue that there is no 

 necessary connection between the size of an object and the 

 value of a fact, and that, though the objects I have 



