APPENDIX H: LYELL 433 



ASSUMPTION OF THE DISCORDANCE OF THE ANCIENT AND EXISTING 

 CAUSES OF CHANGE UNPHILOSOPHICAL 



. . . For more than two centuries the shelly strata of the Sub- 

 Apennine hills afforded matter of speculation to the early geologists 

 of Italy, and few of them had any suspicion that similar deposits 

 were then forming in the neighboring sea. They were as unconscious 

 of the continued action of causes still producing similar effects, as the 

 astronomers, in the case supposed by us, of the existence of certain 

 heavenly bodies still giving and reflecting light, and performing their 

 movements as in the olden time. 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 Al- 

 mighty ; and others ascribed the imbedded fossil bodies to some plastic 

 power which resided in the earth in the early ages of the world. At 

 length Donati explored the bed of the Adriatic, and found the closest 

 resemblance between the new deposits there forming, and those 

 which constituted hills above a thousand feet high in various parts 

 of the peninsula. He ascertained that certain genera of living testacea 

 were grouped together at the bottom of the sea in precisely the same 

 manner as were their fossil analogues in the strata of the hills, and that 

 some species were common to the recent and fossil world. Beds of 

 shells, moreover, in the Adriatic, were becoming incrusted with cal- 

 careous rock; and others were recently enclosed in deposits of sand 

 and clay, precisely as fossil shells were found in the hills. This splen- 

 did discovery of the identity of modern and ancient submarine opera- 

 tions was not made without the aid of artificial instruments, which, 

 like the telescope, brought phenomena into view not otherwise within 

 the sphere of human observation. 



In like manner, in the Vicentin, a great series of volcanic and marine 

 sedimentary rocks were examined in the early part of the last century ; 

 but no geologist suspected, before the time of Arduino, that these 

 were partly composed of ancient submarine lavas. If, when these 

 enquiries were first made, geologists had been told that the mode of 

 formation of such rocks might be fully elucidated by the study of 

 processes then going on in certain parts of the Mediterranean, 

 they would have been as incredulous as geometers would have been 

 before the time of Newton, if any one had informed them that, 

 by making experiments on the motion of bodies on the earth, they 



