302 



of connection, excepting that of superposition, with the sub- 

 jacent rock, give them quite the appearance of extraneous 

 bodies, projected by some unknown cause on the spots where 

 they now repose. 



" There are two theories, on the principles of which the 

 geologists of the present day profess to explain the actual 

 state of the earth's surface; the advocates of one theory 

 maintaining that the dry land was elevated from the bottom 

 of the sea by the expansive force of heat acting from below ; 

 while the votaries of the other assert that the land was 

 formed where it actually exists, and was left dry by the 

 gradual recession of the sea within its present limits, after 

 having, for a long period, covered the highest mountains. 

 Without venturing an opinion on the comparative merits of 

 these theories, as applied to the surface of the ^lobe in 

 general, there are certain facts connected with the Natural 

 History of this island, as well as of Bourbon, that appear to 

 me less repugnant to the principles of the former, than to 

 those of the latter ; and for the explanation of which, I would 

 not hesitate to give it the preference, if I were called on to 

 choose between the two. 



** Their deep narrow ravines, and high precipitous moun- 

 tains; the vast accumulation of angular fragments of a 

 description of rock that appears peculiarly prone to disinte- 

 gration; the almost total want of vegetable soil on their 

 surface, and of alluvium along their shores; the remains, 

 already noticed, of a belt of organic exuviae r^osing on the 

 surface of the ground, though apparently similar to those 

 which are found in other parts of the world, buried deep 

 within the bowels of the earth : these, and their uninhabited 

 state at the era of their discovery, are points which favour, 

 so far as they go, the supposition, that the islands in question 

 are of comparatively recent origin. Now, partial and 

 successive formations of land are conceivable on the prin- 

 ciples of the Huttonian theory. The elevation of the w^hole, 

 indeed, of the present dry land, may be considered as the 

 result of a partial exertion of that power, which, according 

 to that theory, is in constant activity in the central region 



