SECONDARY LIMESTONE. 431 



has arisen, as already noticed in treating of the 

 former, from the lax use of the term transition, 

 which seems too often to have been made a con- 

 venient evasion for difficulties with which the 

 observer was unable or unwilling to cope. It is 

 not therefore in the case of the white limestone 

 of Greece only, which appears to be secondary, 

 that this difficulty has occurred ; and time alone 

 can remedy this and many other defects which 

 unavoidably beset a subject that has hitherto ex- 

 perienced but a very imperfect consideration. 

 There is no one of the sciences in which super- 

 ficial observations are so easy to make and so 

 difficult to detect or verify ; and the use of a very 

 few established terms and phrases, enables the 

 most incompetent observer to throw obscurity, 

 for a long period, over the most simple facts, and 

 to convey the semblance of information without 

 the substance. 



Secondary limestone is much more decidedly 

 stratified than primary, which, it has already 

 been seen, is often found in the form of large 

 imbedded irregular masses. Yet some cases also 

 occur, where the form of stratification disappears, 



