loo MICROSCOPICAL OBJECTS FOUND 



I was able to ascertain, also, that the former had 

 not only been produced, but hardened, prior to 

 the crystallization of the latter ; as in many 

 instances the granules were split acrttss with a 

 clean fracture, sometimes a dozen or more of 

 them being so divided in one line, and the 

 broken portions held asunder by the same crys- 

 talline structure which separated the perfect 

 granules. 



It is easy to conceive, that whilst these strata 

 were in a less consolidated state than at present, 

 they might be charged with water containing 

 carbonic acid gas- This would act as a solvent 

 of the organic atoms of lime until the acid 

 was neutralised, and the fluid saturated with the 

 alkaline carbonate, which would now become 

 obedient to the ordinary laws of aggregation and 

 crystallization ; and, on the recurrence of any 

 material change in the electric condition of the 

 whole, the lime might be redeposited at difi'erent 

 periods, and in a variety of forms, — amorphous, 

 crystalline, or concretionary, depending upon 

 delicate and inappreciable causes, of the nature 

 of which our knowledge is very imperfect.* 



* Most probabl}' these causes are of an electric character. 



