ON MINERAL VEINS. 389 



exception ought to be made in favour of Derbyshire, 

 it is fruitles to ask, till miners have learned to observe 

 more accurately, and geologists, discarding their sy- 

 stems, shall seriously turn their attention to a branch of 

 the science which is most particularly its opprobrium. 



Of the Theory of Mineral Feins. 



On such a foundation it has been attempted to build 

 theories of mineral veins; and, as usual in similar 

 cases where the love of truth has no weight against 

 temper and vanity, the opposing opinions have been 

 maintained with a vehemence proportioned to the 

 want of evidence. Philosophy would shrink into a 

 small bulk indeed, were Truth its object. In stating 

 these hypotheses for the purpose of inquiring into 

 the probability of either, I must premise that the 

 only important question at issue, concerns the manner 

 in which the contents of the veins were formed and 

 introduced. 



It is said, on one hand, that the materials of veins 

 have been deposited from the same universal solution 

 whence the rocks were formed. But there are two 

 modifications of this aqueous theory. While the 

 rocks were in the act of being precipitated, the veins 

 were undergoing the same process ; and hence they 

 are of different ages, corresponding to those of the 

 strata in which they lie. How such an operation was 

 effected is not explained ; but such was of the wor- 

 shipped geology and chemistry of that Germany which 

 founded geological science ; founding it on as solid a 

 basis in all else. In the other modification, the fissures 

 were formed in the rocks by drying, and the minerals 

 were precipitated in them after the deposition of the 

 rocky materials. He who can measure the relative 

 impossibility of two impossibles, may take his choice- 



