188 Prof. Nepomuk Fuchs' Chemical Views regarding' 



accompanies it through all epochs, up to the newest period. In 

 the primitive formations, it is of inconsiderable extent, but after- 

 Avards increases in amount, almost in the same ratio in which 

 the siliceous series diminishes, and makes its appearance in the 

 secondary class of rocks, in masses of immeasurable extent. 

 Limestone is invariably of crystalline origin ; but this can 

 only be distinctly discovered in that of primary periods. The 

 newer limestones are almost always an accumulation of such 

 extremely small crystals, that the latter can only be recognised 

 under a good microscope. This structure presupposes the 

 ])resence of this substance after the creation, in a condition in 

 which it could acquire such a structure. Geologists, and more 

 especially Vulcanists, are thus placed in great perplexity, al- 

 though they do not always acknowledge it. If the earth was 

 in a melted condition, the carbonate of lime must have been so 

 also ; and this, it is believed, may be assumed unconditionally, 

 since we know, that it can really be melted under a certain 

 pressure, without losing its carbonic acid. Nothing can be 

 said against this ; but nevertheless we must remember another 

 circumstance, of great consequence, and one which seems to be 

 forgotten by the Vulcanists, viz. that carbonate of lime and 

 silica cannot exist together in a strong fire, for the carbonic 

 acid must yield to the silica, inasmuch as a silicate of lime is 

 formed. Aluminous silicates, as felspar, mica, &c. act in a si- 

 milar manner on carbonate of lime. 



If, therefore, we assume that all was at first melted to- 

 gether, I would ask the question, if, according to chemical laws, 

 carbonate of lime could have existed without being converted 

 into a siHcate ? Such must evidently have taken place, and 

 we ought, under these circumstances, to meet with hardly any 

 quartz or limestone in the mineral kingdom. But as this is not 

 the case, as silicate of lime is a rare substance, and as pri- 

 mitive limestone not unfrequently contains quartz, mica, fel- 

 spar, &c., the Vulcanists cannot be correct in their views; and 

 as the limestone cannot have been melted, it must have acquired 

 its crystalline structure in another way, viz. by means of water. 



The Vulcanists admit that transition and secondary limestones 

 have been precipitated from water, for they are forced to do so 

 by the petrifactions that are contained in these rocks, and also 



