ANXIVEESARY ADDRESS OP THE PEESIDEXT. 1 1 5 



the materials operated upon were more uniform. Homotaxis is 

 recognized as a great principle in the life-history of the earth ; that 

 a like order should prevail in the development of its earliest rocks, 

 does not seem an iraprohable hypothesis. 



The one path is supported by a considerable number of ascertained 

 facts and a priori probabilities inferred from physical considerations ; 

 the other is strewn with the debris of mistaken observations and 

 exploded hypotheses. The one, though strait and hard, offers some 

 hope of leading us at last to the light of truth ; the other, though at 

 first it seemed broad and easy, has been proved to be the way of 

 darkness and of error. Those who, like myself, have been at the 

 pains of testing the asserted evidence in its favour, know how it 

 has been bolstered up by incorrect observations, unproved assertions, 

 untested assumptions, and inferences founded sometimes on super- 

 ficial similarities, sometimes on a mere juggling with words, which 

 is more worthy of the schools of the sophists than of the earnest 

 searcher after truth. If progress is to be made in this branch of 

 petrology, if the veil that hangs over the first beginning of this 

 globe's history is ever to be raised, it must be done by free and in- 

 dependent investigation, by the most careful scrutiny of nature, by 

 strict attention to the meaning of words, and by the honest and 

 unflinching use of those processes of induction which are the foun- 

 dation of all true science. 



My last duty is to thank you for the patience with which you have 

 listened to this long and somewhat discursive address, and, even more 

 heartily, for the unvarying kindness which, during the last eight 

 years, and especially since I became your President, I have received 

 from the Officers, the Council, and the other Pellows of the Society. 

 I retire from office with a deep sense of the honour which you have 

 conferred upon me, and the friendly spirit in which you have re- 

 ceived my endeavours to serve the Society. So pleasant has the 

 work been made that I might relinquish the chair with some regret 

 did I not greet as my successor a valued friend and colleague, who 

 will fulfil its duties with no less zeal, and who, as a geologist, is 

 more worthy than myself of so great a distinction. 



VOL. XLII. 



