352 Prof. Keilhau on the Formation of 



deeply-seated subterranean agency ; but subsequent examina- 

 tion convinced him, that many of them are veins of segrega- 

 tion ; and he observed some of them fairly terminating at both 

 ends in the limestone. They are most abundant in the proxi- 

 mity of the large concretionary masses. Other larger and ver- 

 tical rents have their walls lined with crystals of calcareous 

 spar, the surfaces of which are coated over with black bitumen. 



If we inquire as to the origin of marble occurring in such 

 a manner, and under such circumstances, it is very evident 

 that neither of the theories generally received can explain the 

 problem. " Fire" is entirely out of the question, and " wa- 

 ter" does not afford us much assistance. The latter has plainly 

 given its aid so far; the formation can, and must, be pro- 

 nounced to be hydrogenic, and we even know, that it was the 

 water of the sea which thus far was in operation. But if 

 it was water which deposited the carbonate of lime, still it 

 could not, even if its power of solution had been rendered 

 ever so great by means of some accidental component part, 

 have produced directly the peculiar calc-spar aggregates, which, 

 in this case, constitute the marble. These masses did not crys- 

 tallize in the sea ; and as assuredly no one, who pays sufficient 

 attention to the geognostical relations just detailed, can ad- 

 vance such an opinion, I shall not stop to refute it. 



But how is the new path to be found, which is here to be 

 trodden % Chemistry does not assist us, for, in the question as 

 to the formation of calcareous spar, it gives no other explana- 

 tion, but either the previous fusion of the carbonate of lime 

 or aqueous solution, in which latter alternative, nothing else 

 is spoken of but water, excess of carbonic acid, and the shoot- 

 ing out of crystals in the liquid. 



Here, then, is one of the instances where, inasmuch as che- 

 mistry, so far at least as has yet happened, firmly refuses to 

 come forward with other propositions, suggestions for a new 

 theory can spring from the geognostical phenomena them- 

 selves. When these are attentively considered, the idea oc- 

 curs of actions that have operated powerfully in masses, which 

 at first were principally mere rough mechanical mixtures, nay, 

 which, perhaps, were not precipitated in a crystalline state at 

 any one point. The view presses itself irresistibly upon us, 



