THE 



EDINBURGH NEW 



PHILOSOPHICAL JOURNAL. 



Address delivered at the Anniversary Meeting of the Geological 

 Society of London, on the 15th February 1850. By the 

 President, Sir Charles Lyell, F.R.S., &c. &c. * 



Gentlemen, — It is now my duty, in accordance with the 

 usual custom of my predecessors in office, to say something 

 of the scientific labours of geologists during the past session. 

 It is nearly twenty years since I announced, in the first 

 edition of my "Principles of Geology," the conviction at 

 which I had then arrived, after devoting some time to obser- 

 vation in the field, and to the study of the works of earlier 

 writers, that the existing causes of change in the animate 

 and inanimate world might be similar, not only in kind, but 

 in degree, to those which have prevailed during many suc- 

 cessive modifications of the earth's crust. I attempted to 

 adapt the views which Hutton and Playfair had first pro- 

 mulgated, to a more advanced state of our science, and to 

 extend their application, by shewing, that should the same 

 causes continue to act with unabated energy, for indefinite 

 periods of the future, they must bring about revolutions not 

 inferior in magnitude to those recorded in the monuments of 

 past ages. After an interval of twenty years, during which 

 Geology has been enriched by a vast accession of new facts, 

 and when so many powerful minds, in every civilized country, 

 have brought their intellectual energies to bear on the philo- 

 sophy of our science, I may I think affirm that the idea of 

 comparing the modern agents of change with those of remote 

 epochs, as not inferior in power and intensity, appears even 



* Copy communicated by the Author. 

 VOL. L. NO. XCIX. — JANUARY 1851. A 



