230 EXPERIMENTS ON METAMOEPHISM AND 



by calculation the flattenini:^ 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 which conceived it.t It was, 

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

 JSpoques de la Nature drew his most profound inspirations;:]: but the 

 works of Buffon, 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. || 



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, Schule, 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 Avhich 

 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 Buffon, as historian of nature, presented only a summary of 

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



De SaussurCjT^ Pallas,*^' and Werner inaugurated, by works nearly 

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

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

 those which were well founded. if 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 Malhematica Philosophice Nalurulis, lf)67. 



fLeibnitz gave a sketch of the dissertation, known under the name of Protogaa, in the 

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

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

 N'Jtural History, that the whole Protogaa was publish(;d. 



XLa Tlieorie de la Terre is dated 1749. Les Epoqucs de la Nature appeared nearly thirty 

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

 the idea of a central heat. 



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

 acknowledged by Mr. Elie de Beaumont.— (Zrfo?i« de Giologie Pratique, p. 24.) 



^Sgstema Naturm, 1775. 



^[De Sau.'-sure was born in 1740. He commenced his travels in 1760, and published in 

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

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



**l'a]las published in 1777 his observations on mountains, and a few years after the nar- 

 rative of his lotig travels. 



fjThese three great observers believed, as did Linnaius, 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 Auvergiie, that he could not admit that biusalt 

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



