THE PROGRESS OP GEOLOGY 417 



Subapenmne hills afforded matter of speculation to the 

 early geologists of Italy, and few of them had any sus- 

 picion that similar deposits were then forming in the neigh- 

 bouring sea. Some imagined that the strata, so rich in 

 organic remains, instead of being due to secondary agents, 

 had been so created in the beginning of things by the fiat 

 of the Almighty. Others, as we have seen, ascribed the 

 imbedded fossil bodies to some plastic power which resided 

 in the earth in the early ages of the world. In what man- 

 ger were these dogmas at length exploded? The fossil 

 relics were carefully compared with their living analogues, 

 and all doubts as to their organic origin were eventually 

 dispelled. So, also, in regard to the nature of the contain- 

 ing beds of mud, sand, and limestone: those parts of the 

 bottom of the sea were examined where shells are now 

 becoming annually entombed in new deposits. Donati ex- 

 plored the bed of the Adriatic, and found the closest re- 

 semblance between the strata there forming, and those 

 which constituted hills above a thousand feet high in 

 various parts of the Italian peninsula. He ascertained by 

 dredging that living testacea were there grouped together 

 in precisely the same manner as were their fossil analogues 

 in the inland strata; and while some of the recent shells of 

 the Adriatic were becoming incrusted with calcareous rock, 

 he observed that others had been newly buried in sand and 

 clay, precisely as fossil shells occur in the Subapennine 

 hills. 



In like manner, the volcanic rocks of the Vicentin had 

 been studied in the beginning of the last century; but no 

 geologist suspected, before the time of Arduino, that these 

 were composed of ancient submarine lavas. During many 

 years of controversy, the popular opinion inclined to a belief 

 that basalt and rocks of the same class had been precipi- 

 tated from a chaotic fluid, or an ocean which rose at succes- 

 sive periods over the continents, charged with the com- 

 ponent elements of the rocks in question. Few will novr 

 dispute that it would have been difficult to invent a theory 

 more distant from the truth ; yet we must cease to wonder 

 that it gained so many proselytes, when we remember that 

 its claims to probability arose partly from the very circuiu- 



(14) HC x.xx vin 



