INTRODUCTION. u5 



superimposed strata thus display to us the faunas and floras of 

 different epochs. In this sense the description of nature is 

 intimately connected with its history; and the geologist, 

 who is guided by the connection existing amongst the facts 

 observed, cannot form a conception of the present without 

 pursuing, through countless ages, the history of the past. 

 In tracing the physical delineation of the globe, we behold 

 the present and the past reciprocally incorporated, as it were, 

 with one another ; for the domain of nature is like that of lan- 

 guages, in which etymological research reveals a successive 

 development, by showing us the primary condition of an idiom 

 reflected in the forms of speech in use at the present day. 

 The study of the material world renders this reflection of the 

 past peculiarly manifest, by displaying in the process of for- 

 mation rocks of eruption and sedimentary strata, similar to 

 those of former ages. If I may be allowed to borrow a strik- 

 ing illustration from the geological relations by which the 

 physiognomy of a country is determined, I would say that 

 domes of trachyte, cones of basalt, lava-streams (coulees] of 

 amygdaloid with elongated and parallel pores, and white 

 deposits of pumice, intermixed with black scoria, animate the 

 scenery by the associations of the past which they awaken 

 acting upon the imagination of the enlightened observer like 

 traditional records of an earlier world. Their form is their 

 history. 



The sense in which the Greeks and Romans originally em- 

 ployed the word history, proves that they too were intimately 

 convinced that to form a complete idea of the present state of 

 the universe, it was necessary to consider it in its successive 

 phases. It is not, however, in the definition given by Valerius 

 Flaccus,* but in the zoological writings of Aristotle, that the 

 word history presents itself as an exposition of the results of 

 experience and observation. The physical description of the 

 world by Pliny the elder, bears the title of Natural History, 

 while in the letters of his nephew it is designated by the 

 nobler term of History of Nature. The earlier Greek his- 

 torians did not separate the descriptions of countries from 

 the narrative of events of which they had been the theatre. 

 With these writers, physical geography and history were long 

 intimately associated, and remained simply but elegantly 

 blended until the period of the development of political inte- 

 * Aul. Gell., Noct. Att. t v. 18. 



