188 u4(!(lress to the Geological Society of London. 



Dynamics. And we have yet to IcarOj wlietlier man's past duration upon 

 the earth, whcthereven that which is still destined to him, issuchas to allow 

 him to philosophize with success in such matters ; — whether, not indivi- 

 duals only, not a generation alone, but whether the whole species be not 

 too ephemeral, to penetrate, by the unassisted powers of its reason, into 

 the mystery of its origin : — whether man, placed for a few centuries on 

 the earth as in a school-room, have time to strip the wall of its coating, 

 and count its stones, before his parent removes him to some other desti- 

 nation. 



And now, gentlemen, I approach the close of my task, and of the 

 office which has been imposed upon me ; an office which has been to me 

 a source of unminglcd gratification. The good opinion implied by your 

 selection of me, the good opinion of such a bodj' of men, was an occa- 

 sion of sincere and earnest self- congratulation, --a self-congratulation hard- 

 ly damped by my consciousness of an imperfect acquaintance with your 

 science ; — since I trusted that you, tliough not unaware of my defects, 

 had judged that good will, and a disposition to look at the subject in its 

 largest aspect, might in some measure compensate for them. And if I 

 needed other grounds of satisfaction in the employment which I am 

 thus bringing to its close, I might find them in the reflections I have just 

 been led to make in the progress and prospects of the science with which 

 you are concerned. For it has ever been one of my most cherished occu- 

 pations, and will, I trust, long be so, to trace the principles and laws by 

 which the progress of human knowledge is regulated from age to age in 

 each of its provinces. To have had brought familiarly under my notice, 

 in a living form, the daily advance of a science so large and varied as 

 yours, has been, as it could not but be, a permanent and most instruc- 

 tive lesson ; — perpctuallj^ correcting lurking mistakes, and suggesting 

 new thoughts. And if, while I have looked at your science in this spirit, 

 you have thought me worthy to be called to preside over your body for 

 two 3'cars ; and if, during that time, you have not repented of your 

 choice, as I have not found my views inapplicable to the subjects Avhich 

 liave come before j^ou ; I may, I would believe, find in this some ground 

 for confiding in the trains of thought which have thus led me to such a 

 position ; and may hope that, however arduous be the task of framing a 

 philosophy of science suitable to its present condition, and of using 

 huch a philosophy as a means of furthering knowledge in general, still, 

 tliat in this task, to which our age is so manifestly called, I too may be u 

 lielper. 



1 trust that you will excuse these few words uttered with reference to 

 my own peculiar pursuits, since these include yours also, and are mj' 

 only claim to your indulgence. And now, gentlemen, that I may tres- 

 ]iass upon that indulgence no longer, I once more thank you in all ear- 

 r fastness and sincerity for your good opinion which placed me in this 

 ( iiair, and for the kindness and support which I have on all occasions re- 

 ceived from you ; and with my best wishes for your prosperity, and that 

 of your science, I resign my office into abler hands. 



