392 ON MINERAL VEINS'. 



insolubility of many of the contents of mineral veins 

 in water, and their production from fusion, they are 

 founded on ignorance of Chemistry; as it is easy to 

 show that many of them are certainly produced from 

 solution, that others may have been generated in this 

 way, and that some of them could not have been con- 

 solidated from fusion. I shall reserve these parti- 

 culars for the end of this-chapter, when the several mi- 

 nerals producible in either mode will be enumerated. 



Whatever objections may be made to the aqueous 

 hypothesis, from the dispositions of the minerals in 

 the veins, they are at least equally valid against the 

 igneous one. It is impossible to comprehend how 

 these several peculiarities could have been produced 

 from a state of igneous fluidity, any more than from 

 a state of solution. It has also been said by the sup- 

 porters of this hypothesis, of whom the ostensible one 

 is well known, that the absence of the solvent from 

 the veins is a proof that their contents were not de- 

 posited from water. It has commonly been supposed 

 a necessary preliminary to correct reasoning, to possess 

 knowledge. Geology has seemed to be exclusively 

 privileged to dispense with it, and thence has it been 

 what it is. Calcareous stalactites, travertinos, veins, 

 quartz veins, chalcedonies, amygdaloidal nodules, are 

 deposits from solution, and the water is equally absent. 

 If this is meant to be an argument from dilemma, the 

 first step is to establish the necessity of the alternative. 



Another groundless chemical argument has been 

 derived from the mutual impression of co-existent 

 crystals in the veins. This is founded on the nature 

 of granite and other rocks, crystallized from fusion ; 

 but it is the misapplication of a fact, through similar 

 ignorance, equally evinced in attempting to explain 

 the nodules of the amygdaloids. I have proved else- 



