Anniversary of 1858. Address of the President. 439 



dress, to refer to a recent repetition of this observation of an identity 

 between the fossils of the east of India and those of the London and 

 Paris basin. I may observe that these, and other contributions to In- 

 dian geology by other writers, contained in the volume of which I 

 spoke, and a preceding one, induced the Secretaries of that time to 

 insert a map, on which the localities of these observations were in- 

 dicated ; and to express in the volume a hope, that these were merely 

 an earnest of the information which might be expected from the 

 activity of British subjects in that quarter*. 



Among our foreign members deceased within the year, I regret 

 much to have to mention one, to whom is due, in no small degree, 

 a revolution in the mode of treating the subject of geology, which 

 has taken place in our own times, and the formation of a new branch 

 of geology. This revolution consists in the endeavour, now so fa- 

 miliar to us, to identify geological with recent changes, instead of 

 classifying the great past changes in the surface of the earth which its 

 structure discloses to us, as separate from the newer and slighter 

 modifications of which history and tradition gives us evidence ; and the 

 study of the discernible causes of change to which we are thus led, 

 I shall have occasion to speak of under the name of Geological Dy- 

 namics. You are well aware that Mr. Lyell is the person who has, 

 with a bold and vigorous hand, moulded the whole scheme of geo- 

 logy upon this idea ; but the power which he had of doing this was 

 derived in no small degree from Von Hoif's admirable survey of the 

 evidence of those changes which can be proved by tradition. The 

 extent and universality of the facts thus brought into notice, might 

 well forcibly strike a philosopher already seeking to apply such a 

 principle to geology ; and Mr. Lyell has always been forward to 

 acknowledge his obligations to M. Von HofF. Indeed the idea of such 

 an identification of geological with historical changes was by no means 

 new; it had been both expressed and acted on by Deluc ; and must 

 have been present to the minds of those persons who framed the ques- 

 tion which gave rise to Von HofF's book. This question was proposed 

 in 1818 by the Royal Academy of Science of Gottingen. " Consider- 

 ing," they said, **that we have, in the crust of the earth, evidence of 

 great revolutions, which have happened at diiFerent times, in dififerent 

 portions, and of which the period and duration are unknown, we are 

 led to ask whether certain more partial alterations may not lie within 

 the domain of tradition, and give us the means of knowing at what 

 period they took place, and what time the formation of certain por- 

 tions of the earth's crust required ; whereby some light may be thrown 

 on those changes which lie beyond the limits of history." 



M. Von Hoff's work, — " The history of those natural changes in 

 the earth's surface which are proved by tradition" — appeared (the 

 first part) in 1822, and had the Academy's prize assigned it. This 

 part of the work contained an account of the changes due to the 

 agency of water ; and by the wide range of reading and study which 



• [Another notice of Mr. Colebrooke has appeared in our present volume, 

 p. 272.— Edit.] 



