Scientific Lectures. qy 



distinction of ocean and of dry land, the latest land being formed from 

 the sednnent distributed by the ocean, until at last we trace back 

 the continent to the tin.e Avlien it was included within this area (indi- 

 catmg tiie northern portion). ^ 



But during all this time we have seen nothing of what has been 

 termed in geology the original nucleus of the globe ; nothing of that 

 crust of matter whicli is tlieoreticallj supposed to have been^]erived 

 trom the slow cooling of a melted mass: nowhere have we dis 

 covered any portion of that disrupted primary mass which has been 

 supposed to fornr the basis ar.d centers of all mountain ranges 

 All that we know, are stratified rocks; stratified from their 

 deposition as sediments in water. The older Laurentian rocks 

 are not only stratified, but they contain fossils and pebbles of 

 pre-existmg stratified rocks. The granites and sienites of the 

 Kocky mountain range are as much stratified, and as trulv of 

 sedimentary origin, as are the rocks of northern ^^ew York or ^^ew 



fx^elTof r "^1" "^^'^ ^'^ '™^^^'°"^ ^' ^"^ --^^-^1^ 

 extent, of sedimentary origin, but we know that there must have 



been pre-existing sedimentary strata, pebbles from which were 

 transported and imbedded in those sediments now constituting the 

 oldest known rocks of the continent. You will see, therefore ''that 

 we go back not only as far as we can absolutely see the l-ocks 

 but still arther, and we demonstrate that there are still earlier 

 periods when there were deposits of sedimentary rocks which 

 are yet to be discovered by geology, of earlier date than the 

 eaniest rocks we know, lower than the lowest rocks we yet know 

 and these being stratified rocks, we may say that water, from the' 

 beginning ot our knowledge, has existed upon the surface of the .lobe 

 We have then no knowledge whatever of the primary nucleus " We 

 see that by the action of water materials have been tmnsported from 

 one part of the surface of the globe to another, covering the former- 

 ocean beds ..th enormous accumulations of sediment ; which after a 

 time, by this change in the relation of the parts, and bv the increase 

 of .emperatu.-e beneath the loaded part, have risen up\and become 

 s ep by step, islands or continents. It is by this process going on, ^.l 

 after age, that the American continent has assumed its preselit f^-m 

 i^ut i desire to impress upon you this one truth: that we have not* 

 in our geological investigation, succeeded in going back one step 

 beyond the existence of water and stratification, one step toward the 

 demonstration of this original so called primary nucleus, a nucleus of 



