History of Geological Opinion. 277 



and are thus intimately relatefl to the physical 

 geography of the time in which we live. 



Thus ends my brief sketch of the geographical range 

 of the geological formations of Britain, in which, for 

 obvious reasons, I have largely directed the attention of 

 the reader to the subject of the Physical Geography of 

 the British area during the epochs in which they 

 were deposited. 



It took a long time, by analyses of the order of de- 

 position of stratified rocks and their contents, for geo- 

 logists to establish the facts and reasonings now generally 

 accepted, and the chief advances have been made in the 

 last eighty years, beginning with the work of Hutton 

 and William Smith. Notices occur in the pages of 

 Herodotus, Aristotle, Strabo, and Pliny, which scarcely 

 amount to geological ideas, but which show that they 

 were cognisant of the occurrence of shells far inland, 

 and high on the mountains ; and they also reasoned on 

 the mutability of the relative levels and positions of sea 

 and land. 



In the fifth century, Orosius, a Spanish divine, re- 

 cognised the true nature of fossil shells, but referred 

 them to the Deluge ; and this opinion for long prevailed 

 among such men as Lister (1683), Burnet (1690), 

 Woodward (1695), and many more besides. Others in 

 Italy (Olivi, 1584, Scilla, 1670, &c.), France, and 

 England (Dr. Plot, 1677), held the absurd opinion that 

 they were ' sports of nature,' the result of the fermen- 

 tation of a ' materia pinguis, or fatty matter ' ; or that 

 4 petrified shells were stones in disguise, formed by the 

 influence of the heavenly bodies.' A few remarkable 

 men held more correct views on the subject. In 1580, 

 6 a potter,' says Fontenelle, ' who knew neither Latin 



