76 THE UNFINISHED BOOK. [1856. 



Snow Mountains. In Australia, the non-volcanic Alps. In 

 North America, the White Mountains, Alleghanies and Rocky- 

 Mountains some of the latter alone, I believe, volcanic. In 

 South America to the east, the non-volcanic [Silla] of Caracas, 

 and Itacolumi of Brazil, further south the Sierra |Ventanas, 

 and in the Cordilleras, many volcanic but not all. Now 

 compare these peaks with the oceanic islands ; as far as 

 known all are volcanic, except St. Paul's (a strange bedevilled 

 rock), and the Seychelles, if this latter can be called oceanic, 

 in the line of Madagascar ; the Falklands, only 500 miles off, 

 are only a shallow bank ; New Caledonia, hardly oceanic, is 

 another exception. This argument has to me great weight. 

 Compare on a Geographical Map, islands which, we have 

 several reasons to suppose, were connected with mainland, as 

 Sardinia, and how different it appears. Believing, as I am 

 inclined, that continents as continents, and oceans as oceans, 

 arc of immense antiquity I should say that if any of the 

 existing oceanic islands have any relation of any kind to 

 continents, they are forming continents ; and that by the 

 time they could form a continent, the volcanoes would be 

 denuded to their cores, leaving peaks of syenite, diorite, or 

 porphyry. But have we nowhere any last wreck of a con- 

 tinent, in the midst of the ocean ? St. Paul's Rock, and such 

 old battered volcanic islands, as St. Helena, may be ; but 

 I think we can see some reason why we should have less 

 evidence of sinking than of rising continents (if my view in 

 my Coral volume has any truth in it, viz. : that volcanic 

 outbursts accompany rising areas), for during subsidence 

 there will be no compensating agent at work, in rising areas 

 there will be the additional element of outpoured volcanic 

 matter. 



Thirdly. Considering the depth of the ocean, I was, before I 

 got your letter, inclined vehemently to dispute the vast 

 amount of subsidence, but I must strike my colours. With 

 respect to coral reefs, I carefully guarded against its being 



