394 ON MINERAL VEINS. 



did not possess chemistry enough to retort the ridicule 

 which they have not themselves spared. If mineral 

 veins have, in any case, been filled hy secretion from 

 the including rocks, there can be no choice between 

 a process which is proved to exist, and one which is 

 unintelligible. 



It has also been said that the solidity, or fulness, 

 of mineral veins could have happened only from 

 igneous injection ; as the abstraction of the water 

 after deposition, must have left cavities or vacuities 

 of some kind. With no small want of reflection, it 

 has further been asserted, that cavities could have 

 been formed in them only on the igneous hypothesis, 

 from the disengagement of elastic fluids. These, it is 

 plain, are the conflicting statements of forge tfulness. 

 The fact, such as it is, is quite as explicable on the 

 one hypothesis as on the other, and is alike worthless 

 to both; while the want of marks of gradual and 

 regular deposition, is a negative which, if it proves 

 one hypothesis to be wrong, does not render the other 

 right. Such are the objections to an hypothesis which, 

 however it might be deemed a necessary part of the 

 general theory to which it belongs, does not involve 

 the igneous origin of granite and trap, nor the eleva- 

 tion of the strata through heat. It has been the error 

 of this, as of all other hypotheses, on all subjects, and 

 at all times, to force all things into conformity to 

 itself, without regard to facts, and without considering 

 what was to be the gain. I should have considered 

 this discussion as a mere waste of words had it not 

 been for the strength of assertion which has been 

 brought into this question on opposite sides; and if 

 it proves nothing, it must be recollected that to show 

 the existence of falsehood in these cases, is the first 

 step towards truth. 



