Russell Institution, 3 1 5 



all the valleys and cavities on the earth's surface, and would 

 not have been confined to the narrow fissures or veins in 

 which they arc found. There are, however, lie observed, 

 existing facts equally decisive against the theories of Dr. 

 Hutton and Mr. Werner respecting the formation of veins. 

 It is almost universally found, that where a metallic vein 

 passes through a mountain composed of beds or strata of 

 different kinds of rock, the nature or quality of the ore 

 varies in each kind of rock. This is the case in Cornwall : 

 where the same vein traverses grau-wacke or killas and 

 granite, it is found to be more rich in the latter rock. In 

 Derbyshire, the veins of galena which pass through the 

 limestone rocks disappear in the basaltic aiiiycdaloid by 

 which the lime rocks are separated ; or, if the vein passes 

 through the amygdaloid, it very rarely contains any quantity 

 of metallic ore. It is also found that different strata or 

 layers in the same bed of lime rock are more productive 

 in ore than others. If metallic veins were filled bv in- 

 fusion from above, or ejected from below, it is impossible 

 that the nature of the rocks they traverse could alter the 

 quality or quantity of their products. Tiiis fact, thouah 

 undeniable, has never, Mr. B. observed, been properly at- 

 tended to, and is alone decisive against the received opinions 

 respecting the formation of nretallic veins, and seems to 

 prove that the rock itself has been in some manner opera- 

 tive in the production of their contents. 



Mr. B. observed, that the present state of chemical 

 science did notadrriit us to form any decisive or satisfactory 

 opinion on this subject, and he considered it much wiser 

 to acknowledge our ignorance, than frame theories which 

 only serve to perpetuate error. It is not at present fully 

 ascertained, whether metals be simple substances, or com- 

 pounds : but this discovery, he said, must precede the 

 formation of such a theory as will explain in a satisfactory 

 manner many of the mysteries in the mineral kingdom. 



Some experiments which he showed, offered, he said, 

 hints to future discoveries on this subject. All the metals 

 are capable of existing in peculiar solutions, and some of 

 them (perhaps all) are akso capable of becoming elastic in- 

 visible gases when united with hydrogen, and can be made 

 to deposit the trietallic contents in a solid form. In this man- 

 ner they may have entered veins, and may have been sepa- 

 rated from the substance of rocks, and decomposed by a 

 process analogous to that of the Voltaic electricity, the 

 different sides of the vein acting like the opposite ends of 

 tlie pile. 



X 2 Mr. 



