THE EVOLUTION OF PETROLOdlCAL IDEAS.' 



By J. J. Harris Teall, Esq.. M. A., V. P. R. 8. 



INTRODUCTION. 



The nineteenth centuiT, whose obsequies Me have so recently cele- 

 brated, was born in what has been aptly termed b}^ Professor Zittel, 

 our latest historian, the heroic age of geology. Geological societies and 

 geological survejs did not then exist. Cooperative work was unknown; 

 but a few individuals, of great power and originality, were laying the 

 foimdations of our science on a firm basis of accurate observation 

 Pallas had recently carried out his remarkable researches in eastern 

 Russia, and had noted the extraordinary abundance of the remains of 

 the mammoth, rhinoceros, and bison in the superticiai deposits of the 

 Siberian plains. De Saussure had climbed Mont Blanc, and published 

 his unrivaled descriptions of Alpine scenery and Alpine structure. 

 Werner was still acting as an exponent of the science which he had 

 done so much to foster, and had fired his two most illustrious pupils, 

 L. von Buch and Humboldt, with that enthusiasm for natural knowl- 

 edge which was destined to produce such glorious results. Hutton had 

 just passed away, after giving to the world his Theory of the Earth, 

 the main features of which form the basis of modern geology. Smith 

 and Cuvier, both born in the same year (1769), were in the prime of 

 life, and actively engaged in those researches which placed stratigraph- 

 ical geologv on a secure foundation. These are some of the heroes of 

 our science. 



The early history of geology is mainly a record of fantastic specu- 

 lations; but in the heroic age it was beginning to be recognized that 

 no solid advance could l)e made except on a basis of carefully observed 

 fact. A reaction against the wild speculations of the seventeenth and 

 the greater portion of the eighteenth centuries had set in, and this led, 

 among other things, to the foundation of our society — the parent of all 

 such societies — in 1807. 



« Reprinted by permission of the author and of the society from Proceedings of the 

 Geological Society, London, vol. i.vii, pp. Ixii-lxxxvi, May, 1901. Anniversary 

 address of the president of the society. 



2S7 



