372 MEMOIR OF LEOPOLD VON BUCH. 



his birth, and the view of those fair scenes which he animated with the memo- 

 ries of his youth, phmged him into reverie. It was observed that he passed 

 a long night in deep meditation, in which he seemed to address to the places 

 he was regretfully leaving a touching and silent adieu. 



He came once more, however, to visit France, whose genius he loved, and to 

 sit in that Academy to which he prided himself in belonging. He left Paris 

 only in the last days of 1852, and peacefully breathed his last in the spring of 

 1853. 



Von Buch, who had qualified himself for the direct contemplation of nature 

 by always and everywhere pursuing her indications, has left us an example of 

 one of the noblest of scientific careers. He had the happiness to consecrate a 

 long life and a penetrating genius to the profound and unwearied study of one 

 of the highest questions of natural philosophy. Descartes had suspected 

 the igneous origin of the globe;* Leibnitz had inferred its incandesccncet 

 fi-om the traces everywhere apparent of a vast pristine fusion ; BuiFon| had 

 demonstrated the existence of the primitive fire, still subsisting, and more and 

 more concentrated in the interior of the earth ; Dolomieu§ finally had pro- 

 nounced before this Academy the words adopted by Lagrange :|| "This 

 globe, at first incandescent and fluid throughout its whole mass, is still so in 

 its interior, and has nothing solid but its crust;" but no one more contributed 

 than Von Buch to prepare the vast and sublime generalization which dares to 

 place in this profound and central fire, of Avhich, however, he himself has 

 nowhere pronounced the name or fully admitted the idea, the first and sole, 

 the potent and terrible cause of all the revolutions of our globe. 



The author thinks it his duty to acknowledge the assistance he has derived, 

 in preparing the above memoir, from the eloquent and learned Notices of the 

 great geologist, published in Germany, by MM. Geinitz, professor of the Poly- 

 technic School of Dresden ; Gotta, jirofessor of the School of Mines of Prey- 

 berg ; Dechen, director of mines at Bonn ; Noggeratli-, professor at the Uni- 

 versity of Bonn, and a fifth, anonymous, pronounced April 6, 1853, before the 

 Geological Society of Germany. 



* "Let us suppose that this earth on which wo reside has been once a star composed of 

 matter of the first element absohitely pure, so that it diftered in nothing from the sun except 

 in being smaller." — (Descartes: Les Principes dc la Philosophic, IV part.) 



t "It seems that this globe has been once on fire, and that the rocks which form the 

 base of this crust of the earth are scoria remaining from a vast fusion." — (Leibnitz : Proto- 

 gcea, &c. ) 



X "The internal heat of the globe, still actually subsisting, proves to us that the ancient 

 fire which the earth has sustained is not yet by any means entirely extinct; the surface is more 

 cooled down than the interior. Conclusive and repeated experiments assure us that the entire 

 mass of the globe has an inherent heat, altogether independent of that of the sun. This heat 

 we recoo-nize in a palpable manner as soon as we penetrate into the interior of the earth, and 

 it augments in proportion as we descend." — (Buffon: Epoqucs de la Nature.) 



§ "While insisting on facts which seem to me of great importance, and again repeating 

 that the unknown cause which produces the fluidity of lavas appears to me to exist imder 

 the consolidated envelope of the globe, I should add that it is not without design that I em- 

 ploy the expression consolidated envelope; for if I cannot doubt that our globe has once been 

 fluid, there is nothing to prove to me that there can be anything consolidated about it but a 

 crust more or less thick ; nothing to show that the consolidation, which has been necessarily 

 progressive, has yet attained the centre of this spheroid. I regard the general opinion which 

 ascribes a solid nucleus to our globe as a gratuitous hypothesis, and the opposite hypothesis 

 appears to me much more probable, since with it we can explain a multitude of important 

 facts which, without it, are inexplicable." — (Dolomieu: Rapport fait dV Institut national sur 

 ses voyages de Van V, VI. — Journal de Physique, 1798.) 



y "The suftrage of the illustrious Lagrange is of too great weight and too flattering not to 

 be insisted on when one has had the good fortune to obtain it. It was not without much 

 timidity and circumspection that I hazarded this hypothesis before my colleagues, when the 

 celebrated geometer, warmly seconding my opinion, asserted that it was not only highly 

 tenable, but that to him it appeared the more probable inasmuch as there seemed to be nothing 

 in dii-ect opposition to it."— (Dolomieu: Ibid.) 



