SIR CHARLES LYELL, HART. 169 



be attributed to Ly ell's intimacy with the late Sir 

 Roderick Murchison, a journey with whom, taken 

 in 1828, was especially fruitful in results. This alone 

 "gave rise to two distinct papers on the volcanic 

 district of Auvergne and the Tertiary formation- of 

 Aix- en- Provence ; but it was apparently while examining 

 Signor Bonelli's collection of Tertiary shells at Turin, 

 and subsequently when (after parting with Murchison) 

 he studied the marine remains of the Tertiary rocks of 

 Ischia and Sicily, that Lyell conceived the idea of divid- 

 ing the Tertiaries into three or four principal groups, 

 characterized by the proportion of recent to extinct 

 species of shells. To these groups, after consulting Dr. 

 Whewell as to the best nomenclature, he gave the names 

 now universally adopted — Eocene (dawn of recent), 

 Miocene (less of recent), and Pliocene (more of recent) 

 Upper and Lower; and with the assistance of M. 

 Deshayes, who had arrived by independent researches 

 at very similar views, he drew up a table of shells in 

 illustration of this classification." 



In the "Elements," therefore, he described those 

 monuments of ancient changes through which the earth 

 and its inhabitants have passed, whilst in the "Prin- 

 ciples' he confined himself to the study of those forces 



says a writer in the " Encyclopaedia Britannica," " with 



new material and the results of riper thought as to form 

 a complete history of the progress of geology during 

 that interval. Only a few days before his death Sir 

 Charles finished revising the twelfth edition, which 

 appeared in 1876." 



