UOMAIN VII. COMPOSITE. 



structed : the stones must not only be 

 hewn out of the quarry, but most accu- 

 rately squared, before the temple can be 

 erected. But true science and theory are 

 so completely opposite, that any attempt 

 to blend them has always defeated its ob- 

 ject. 



To Mr. Jameson we are greatly indebted 

 for a more ample account of the Wernerian 

 theory of rocks, which he has illustrated 

 with considerable care and attention, so as 

 to form by far the most complete treatise 

 on the subject which has yet appeared. 

 But an infinite number of rocks occur in 

 nature, which have neither name nor local 

 habitation in the Wernerian system, nor in 

 the Huttonian ; though no science can be 

 called complete without enumerations of 

 all its objects, and in the present instance 

 one neglected rock might perhaps suffice 

 to overturn a theory. The greatest mis- 

 fortune in the progress of human know- 

 ledge has always been, that theories have 

 been constructed before facts have been 

 observed- The theories are indeed useful, 



