Biographical Memoir of Peter Simon Pallas. 227 



change in the asjxitt of zoology ; and in that of the theory of the 

 earth he effected a real change. An attentive consideration of the 

 two great mountain chains of Siberia enabled him to discover the 

 great law which has since been found to hold good universally, 

 of the succession of the three primitive orders of mountains, the 

 granitic in the middle, schistose on their sides, and limestone 

 mountains outermost. It may be said, that this great fact, dis- 

 tinctly expressed in 1777, in a memoir * read to the Academy 

 in the presence of Gustavus III. of Sweden, was the origin of 

 the present system of geology : Saussure, Dcluc and Werner, 

 set out from it to arrive at the true knowledge of the structure 

 of the earth, so different from the fanciful ideas of preceding 

 writers. 



Pallas, besides, rendered a very great service to geology by his 

 second Memoir on the Fossil Bones of Siberia -f, in which he 

 brings together all that he had observed concerning them during 

 his journey, and especially relates the fact, then almost incredi- 

 ble, of a rhinoceros having been found entire in the frozen 

 earth, with its skin and flesh. The elephant discovered on the 

 sea-shore in a mass of ice, and in such good preservation that 

 the dogs eat its flesh, has confirmed this important observation, 

 and given the final blow to Buffon''s theory regarding the gra- 

 dual cooling of the polar regions. 



Pallas was not so happy in his hypothesis of an eruption of 

 waters coming from the south-east, which might have transport- 

 ed and buried in the north the animals of India. It is now 

 clearly demonstrated, that the fossil animals are very different 

 from those of India. ^-^^^^ 



The great mass of iron which he observed near the Jenissei^ 

 was also an entirely new phenomenon in mineralogy J. This 

 mass lay isolated on the surface of the ground, on the summit 

 of a mountain, far from any vestige of a volcano or of mining 

 operations. It weighed 1600 pounds. The metal, which wa& 

 perfectly malleable when cold, was vesicular, and contained vi- 

 treous matters §. The Tartars said it fell from heaven, and re- 



• Observations on the Formation of Mountains ; Act Petrop. 1778. Pars 

 I. &c.; and separately in 12mo. Petersburg, without date, reprinted at Paris 

 in 1770 and 1782. 



t Nov. Comm. Petr. xviL % Act Petrop. Pars I. 



§ Thia vitreous matter is olivine.— Ed. 



