150 



Triassie period, we have another flora, whilst new forms of fishes 

 and niollusks indicate an approach to that period when the seas were 

 tenanted by Belemnites and Ammonites, marking so broadly these 

 secondary deposits with which British geologists have long been 

 familiar, and which, commencing vrith the Lias, terminate with the 

 Chalk. And lastly, from the dawn of existing races, we ascend 

 through successive deposits gradually becoming more analogous to 

 those of the present day, until at length Ave reach the bottoms of 

 oceans so recently desiccated, that their shelly remains are undistin- 

 guishable from those now associated with Man, the last created in 

 this long chain of animal life in which scarcely a link is wanting ! — 

 all bespeaking a perfection and grandeur of design, in contem- 

 plating which we are lost in admiration of creative power. 



Such results, grand as they are — nothing less in short than the 

 records of creation — are however but a portion of the labours of 

 geologists. They have also struggled to explain the causes 

 of those great revolutions. In some continents, it is true, the 

 pages in the book of nature are, as it were, unruffled; for, by 

 whatever agency effected, it is certain that beds of vast ancient 

 oceans have been so equably elevated and depressed, and again so 

 steadily elevated from beneath the sea, that the continuity of their 

 rocky deposits over areas larger than our kingdoms of Western 

 Europe is unbroken, and their original condition almost entirely 

 preserved. In other regions, on the contrary, the sediments in the sea 

 and the masses of the land have been pierced by numerous out- 

 bursts of igneous and gaseous matters, accompanied by violent 

 oscillations and breaks, whereby the chronicles of succession have 

 been sorely defaced, and often rendered more illegible than the most 

 carbonized of the papyri found under the lava of Vesuvius. Naj^, 

 so intensely has this metamorphism operated, that obliterating all 

 vestiges of former life, and concealing them from us, we have been 

 sorely puzzled to ascertain by what powerful physical agency such 

 mighty changes can have been accomplished, — changes by which 

 the sti-ata have been convoluted into forms grotesque as the serpent's 

 coil, inverted in their order, or shivered into party-coloured and 

 crystalline fragments. And yet in these broken and mineralized 

 masses, as another branch of our science teaches, are found the 

 precious ores and the metals most useful to mankind. 



Such complicated relations and such changes in original structure 

 call forth the application of the highest powers of physical science ; 

 not only involving the agency of that great central heat, to which 

 geologists have willingly referred, but also invoking the aid of 

 agents, some of them still mysterious, by which electricity and mag- 

 netism are bound together in the C3rcle of terrestrial phssnomena. 

 To few of us is it given to venture with firm steps into that region ; 

 and, though I hope to live to see some of these questions answered, 

 I am Avell satisfied to have been among you M'hen such solid ad- 

 vances have been made, in deciphering the mutations of the surface 

 of the earth, and in the compilation of a true history of its earlier' 

 inhabitants. 



