18 Mr. R. W. Fox's Remarks on Mineral Veins, <$-c. 



the commonly smooth surfaces of their containing sides, or 

 " walls," and the rarity of stalactitical forms in them, equally 

 forbid the idea of the contents of veins having once flowed 

 down their sides or exuded from them. Nor are there any 

 instances that I am aware of, of even the smallest veins, how- 

 ever great their inclination, exhibiting extensive open fissures, 

 in consequence of the upper part being closed up or choked 

 by depositions from above. 



It may be remarked, that the contents of veins are not ar- 

 ranged according to their specific gravity, the metalliferous ores 

 being commonly found in detached masses, sometimes near the 

 surface onlj', and at other times at considerable depths, or they 

 ai-e dispersed in the veins at various depths. Frequently, ores of 

 different kinds, which would combine immediately if in fusion, 

 are found in contact, but in entirely distinct masses. Many 

 of these combinations would be instantly decomposed by a 

 great degree of heat; and clay, which is so pi'evalent in veins, 

 cannot be supposed to have an igneous origin. 



Thus I think it may be asked, if the theories which have 

 been advanced on this subject be calculated to remove some 

 difficulties, do they not substitute greater in their stead ? 



The curious arrangement of veins, and the geological struc- 

 ture of the earth, seem to me to afford ample evidence of de- 

 stg7i; and I cannot but believe that the operations of Nature 

 under the surface, as well as above it, are intimately con- 

 nected, and that they equally derive their origin from Divine 

 wisdom and creative power. 



It is a very remarkable fact, that veins are in a considerable 

 degree, either coincident with, or at right angles to the mag- 

 netic meridian. 



In Cornwall and Devon, copper and tin veins are instances 

 of the latter; and those of clay, quartz, &c. of the former. 

 Lead and silver ores, &c. are usually found in north and south 

 veins, when they occur in the neighbourhood of those of cop- 

 per and tin. In some parts of Cornwall, however, instances 

 have occurred of lead veins assuming nearly the E. and W. 

 direction, but I am not aware that any copper and tin veins 

 are known to exist in their immediate neighbourhood. I be- 

 lieve the lead veins generally run from about E. to W. in 

 Wales, and in some parts also of the North of England. This 

 is likewise the prevalent direction of the great silver veins in 

 Mexico. The same observation applies to the veins in many 

 mining districts in Europe. 



This may be taken as the most common direction of the 

 principal metalliferous veins in different districts, as far as my 



information 



