74 Reviews— ZitteV s Century of Geology^ etc. 



unrecognized and they were attributed to a certain ' vis plastica,' and 

 considered to have been directly produced in the ground where they 

 were met with. Even when they were seen to be the remains of 

 extinct animals, they were supposed to have reached their position 

 in the rocks through the action of Noah's Deluge ! The palaeontology 

 of this period did not advance beyond dry, detailed descriptions of 

 fossils, with fantastic speculations as to their origin, and their relation 

 to the sacred scriptures. 



Amongst the writers of this period whose observations of 

 geological facts and whose views of the origin and history of 

 the earth are placed before us by the author, we find the names 

 of Leonardo da Yinci, Giordano Bruno, Nicholas Steno, Burnet, 

 John Woodward, Scheuchzer, John Ray, Charpeiitier, and Guettard ; 

 whilst amongst those distinguished for their observations on volcanoes 

 and earthquakes occur the names of Delia Torre, Desmarest, Sir W. 

 Hamilton, and Faujas de St. Fond. 



In the concluding part of the chapter on this period a summary of 

 the views of Buffon on the theory of the earth is given, with an 

 appreciative reference to the position which this great French 

 philosopher occupies in geological history. As an original, 

 investigator and observer his claims were limited, but he under- 

 stood the significance of facts, and possessed a marvellous capacity 

 of marshalling them in support of his theories. He was incontest- 

 ably the most genial representative of that speculative movement, 

 held in high repute in the sixteenth, seventeenth, and eighteenth 

 centuries, which set itself to solve its problems in a deductive way. 

 With Bufibn there closed a period which had indeed gathered 

 together a large store of materials needful for the earth's history, 

 and had moreover arrived at the conviction that the data for 

 that history might be obtained from the earth itself. But the 

 key for the determination of a chronological succession of events 

 on our planet had not as yet been discovered, no satisfactory 

 insight as to the composition and building up of the earth's crust 

 had been obtained, nor of a regular succession of the fossil remains 

 found within it. 



With the third period of the heroic age of geology, placed by 

 the author in the thirty years from 1790 to 1820, there commences 

 an epoch when facts were recognized and sought after as the only 

 sure foundation for theory, and a corresponding appreciation was 

 placed on the investigation and description of the phenomena of 

 the earth's crust which are within the limits of human observation. 

 Amongst the imposing host of geologists of this period whose works 

 are passed under review occur the names of Werner, Pallas, Saussure, 

 Button, Playfair, William Smith, Leopold von Buch, Alexander vou 

 Humboldt, Alex. Brongniart, and Cuvier. Perhaps the most 

 conspicuous amongst his contemporaries is the celebrated Freiberg 

 Professor, A. G. Werner, of whose teachings and of the wonderful 

 influence which he exercised on his students a very graphic account 

 is given by the author. It is difiicult to realize at the present day 

 that the teaching of Werner that all the rocks of the earth's crust 



