AND STRATIFICATION. 73 



must be considered of a partial nature, and which 

 have been called basins ; and the coal series, in most 

 situations, presents conspicuous examples of it, which 

 have often been much misapprehended. 



It is a general remark, that on opposite sides of a 

 hill or of a ridge, even though it should be a moun- 

 tain of granite, the same series of strata will occur 

 in a corresponding order : deposited on it in two 

 places by one general law, according to some geo- 

 logists, but being one series separated by its inter- 

 position, according to the views entertained in this 

 work. Yet, in some situations, the strata on oppo- 

 site sides of a ridge differ ; and this may be explained 

 by considering them as separate deposits that have 

 been formed from different original sources in dif- 

 ferent cavities or basins. 



This fact, under various modifications, is of very 

 common occurrence, and contradicts the doctrine of 

 universal formations ; the imaginary nature of which 

 is noticed when treating of the order of succession 

 among strata. (Chap, xiv.) The wish to extend ana- 

 logies is perhaps natural to the human mind ; and, 

 in this case among others, it has had an unfortunate 

 effect in Geology. It thus becomes the object of the 

 observer, not so much to investigate accurately and 

 describe carefully what is before him, as to decide 

 whether a stratum belongs to this or the other of 

 some series which he has made his standard of com- 

 parison. Thus even the accurate English geologist 

 may fall under the reproach which has been pecu- 

 liarly bestowed on Werner ; rinding a Britain where - 

 ever the latter discovered a Saxony. " Affingit paral- 

 lela et correspondent et relativa quae non sunt," is 

 the censure which Bacon has applied to philosophers 



