36 



THEOEY OF STENO. 



[Ch. III. 



Steno, 1669. 



remar 



was published by Steno, a Dane, once professor of anatomy at 



many 



the Grand Duke of Tuscany. His 



title of ' De Solido intra Solidum naturaliter contento (1669)/ 



by which the author intended to express, ' On Gems, Crystals, 



and organic Petrifactions inclosed within solid Rocks. 



This 



work attests the priority of the Italian school in geological 

 research ; exemplifying at the same time the powerful ob- 

 stacles opposed, in that age, to the general reception of 

 enlarged views in the science. It was still a favourite dogma, 

 that the fossil remains of shells and marine creatures were 

 not of animal origin ; an opinion adhered to by many from 

 their extreme reluctance to believe, that the earth could 

 have been inhabited by living beings before a great part of 

 the existing mountains were formed. In reference to this 

 controversy, Steno had dissected a shark recently taken from 

 the Mediterranean, and had demonstrated that its teeth and 

 bones were identical with many fossils found in Tuscany. 

 He had also compared the shells discovered in the Italian 

 strata with living species, pointed out their resemblance, and 

 traced the various gradations from shells merely calcined, or 

 which had only lost their animal gluten, to those petrifac- 

 tions in which there was a perfect substitution of stony matter. 

 In his division of mineral masses, he insisted on the secondary 

 origin of those deposits in which the spoils of animals or 

 fragments of older rocks were inclosed. He distinguished 

 between marine formations and those of a fluviatile character, 

 the last containing reeds, grasses, or the trunks and branches 

 of trees. He argued in favour of the or 

 of sedimentary deposits, attributing their present inclined 

 and vertical position sometimes to the escape of subterranean 

 vaxm-iira Tipn.vi-ncy +Tia nrnflf. of the earth from below upwards, 



t> 



masses 



ranean cavities. 



He declared that he had obtained proof that Tuscany must 

 successively have acquired six distinct configurations, having 

 been twice covered by water, twice laid dry with a level, 





