230 EXPERIMENTS ON METAMORPHISM AND 



by calculation the flattening which the terrestrial spheroid* should 

 present, and this idea was also adopted by Halley. 



Still later, Leibnitz, stimulated both by the ideas of Descartes and 

 the very judicious observations of Stenon, published a work which, 

 notwithstanding the inevitable paucity of the facts on which it was 

 founded, bears the stamp of the genius Avhich conceived it. t It was, 

 without doubt, from this source that the illustrious author of Les 

 Epoques de la Nature drew his most profound inspirations;! but the 

 works of BuflFon, although exciting the attention in the highest de- 

 gree, were not calculated to convince, but to strike the imagination 

 very forcibly, and thus provoked precise observations destined to 

 solve the doubts which they had raised. II 



It was not in reality until the end of the last century, at the same 

 epoch when there was opened up for chemistry so new an horizon by 

 the discoveries of Lavoisier, Schiile, Priestley, and Cavendish, that 

 the history of the globe began to disengage itself from preconceived 

 opinions, and that observation began to take the place therein which 

 belonged to it. The exact facts which men endowed with a genius 

 for observation, such as Agricola, Bernard de Palissy, and Stenon had 

 before signalized, were merged in an ocean of hypothesis. The 

 ideas concerning the history of the earth, published by Linnaeus, the 

 rival of Bufifon, as historian of nature, presented only a summary of 

 the facts known and the ideas in vogue at that period. § 



De Saussure,1F Pallas,** and Werner inaugurated, by works nearly 

 contemporaneous, the era of positive geology, and all these disapprov- 

 ing emphatically of the boldness of Buffon, opposed his ideas, even 

 those which were w^ell founded. ft Of these savants, all eminent ob- 

 servers, the two first were sparing of their inductions. But Werner 

 went further : he tried to analyze, to classify, and to co-ordinate facts, 

 and to describe them in definite and precise language, and gave to 

 the science the name of geognosy in contradistinction to geology, 



^Principia Mathematica Philosophice Naturalis, 1667. 



■j-Leibnitz gave a sketch of the dissertation, known under the name of Protogcea, in the 

 Acta EruditoTum, in the month of January, 1693 ; but it was not until thirty-tlaree years 

 after his death, in 1749, the very year that Buffon published the first three volumes of 

 Natural History, that the whole Protogcea was published. 



XLa Ihearie de la Terre is dated 1749. Les Epoques de la. Nalure appeared nearly thirty 

 years later, in 1778. Before Buffon, Mairan, having a special object in view, had developed 

 the idea of a central heat. 



I] The influence which Buffon exercised over the progress of geology has been deservedly 

 acknowledged by Mr. Elie de Beaumont. — (Lirons de G6ologie Pratique, p. 24.) 



^Systema Natures, 1775. 



^De Saussure was born in 1740. He commenced his travels in 17(30, and published in 

 1779 the first volumes of his Voyage dans les Alpes, where he has recorded so many im- 

 portant facts which have served, as it were, for the foundations of geology. 



'^■"'Pallas published in 1777 his observations on mountains, and a few years after the nar- 

 rative of his long travels. 



f fThese three great observers helieved, as did Linnseus, that the strata were formed by 

 aqueous action, and that the volcanic phenomena were simply local accidents. De Saus- 

 sure declared, in 1798, after having visited Auvergne, that he could not admit that basalt 

 was of igneous origin, much less could he admit this origin for granite. 



