72 COSMOS. 



natural forces, together with the phenomena which they pro- 

 duce. 



But if we would correctly comprehend nature, we must not 

 entirely or absolutely separate the consideration of the present 

 state of things from that of the successive phases through 

 which they have passed. We can not form a just conception 

 of their nature without looking back on the mode of their for- 

 mation. It is not organic matter alone that is continually un- 

 dergoing change, and being dissolved to form new combina- 

 tions. The globe itself reveals at every phase of its existence 

 the mystery of its former conditions. 



We can not survey the crust of our planet without recog- 

 nizing the traces of the prior existence and destruction of an 

 organic world. The sedimentary rocks present a succession 

 of organic forms, associated in groups, Avhich have successive- 

 ly displaced and succeeded each other. The different super 

 imposed strata thus display to us the faunas and floras of dif- 

 ferent epochs. In this sense the description of nature is inti 

 mately connected with its history ; and the geologist, who is 

 guided by the connection existing among the facts observed, 

 can not 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 languages, 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 peculiar- 

 ly manifest, by displaying in the process of formation rocks of 

 eruption and sedimentary strata similar to those of former 

 ages. If I may be allowed to borrow a striking 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 scoriae, animate the scenery by the as- 

 sociations of the past which they awaken, actmg 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 



