﻿ANNIVERSARY ADDRESS OF THE PRESIDENT. liii 



the whole physical system of the globe. He established principles, 

 which, in so far as they are fundamental, are now universally 

 admitted." 



I trust that I shall be pardoned in thus giving prominence to a 

 tribute offered, at this distance of time, by so eminent a foreign 

 geologist, to the genius and sagacity of Hutton, of whose ingenuity, 

 acuteness, and even light-hearted playfulness, I had been accustomed 

 in my early life to hear much in my own family, although too young 

 to have any personal intercourse with him ; and in whose scientific 

 principles I was trained in my geological studies under the guidance 

 of my venerated friend the able and eloquent Playfair. I am, how- 

 ever, not prepared to agree with M. Daubree that a shade has been 

 thrown over Hutton's " noble conception " that a continuous process 

 of decay and renovation of the materials of our globe had from the 

 origin of the stratified rocks been the established order of nature ; 

 that observations since the time of Hutton have demonstrated any 

 interruption to that continuity in past time, or justify any anticipa- 

 tion of a future change. 



In this work, as well as in the more recent one of M. Delesse, 

 metamorphism is not limited to the class of rocks to which the term 

 metamorphic was originally applied : on the contrary, M. Daubree 

 expressly says, " Des effets de Taction metamorphique se montrent 

 dans les terrains de divers ages " (p. 119), and, at p. 74, that '" les 

 depots metalliferes ne sont que des cas particuliers des phenomenes 

 metamorphiques." These three essays, in place of being called 

 " Etudes sur le Metamorphisme," might have had, in my opinion, 

 the more appropriate and comprehensive title of" Contributions to the 

 Chemistry of the Mineral Kingdom." And most valuable contribu- 

 tions they assuredly are ; for the facts and experiments they narrate 

 enable us to form some just conception of the agencies by which the 

 lower sedimentary deposits became changed into hard and crystalline 

 rocks, and how their included accessory minerals may have been pro- 

 duced ; they are also calculated to throw light upon the analogous 

 changes of structure met with in the fossiliferous strata of all ages, 

 but which must have been produced underveryclifferent circumstances, 

 and likewise upon the formation of the various products of mineral 

 veins. Even a short summary of the contents of these essays would 

 of itself amount to a treatise ; so I must refer you to the works them- 

 selves, noticing only some of the conclusions of the authors to which 

 I wish to call your attention. 



M. Delesse certainly states that the agencies in general metamor- 

 phism must have been heat, water, and pressure ; but the main 

 feature in both his essays is the prominent part which he considers 

 water to have played in the production of mineral compounds. He 

 brings forward many facts for which the sole action of heat appears 

 to afford an inadequate explanation ; but, on the other hand, he seems 

 to be carried away by his theory to ascribe far too extended an 

 operation to aqueous causes. Thus, he affirms it as his opinion that 

 the trap of the Giant's Causeway was not incandescent and in a 

 state of igneous fusion when it was poured over the lignite it covers ; 

 and in referring to the Meissner, near Cassel, so long celebrated as an 



