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Although this current was many feet in thickness, the little 

 bluff or table rock, is all that remains of it ; as the volcano 

 which^furnished it, and the flow of which this is a part, dis- 

 appeared below the sea. 



Islands thus formed by upheaval are likely to disappear as 

 suddenly. Most of them do so after a longer or shorter pe- 

 riod, either by being abraded by the constant wash of the 

 waves, or disintegrated by the elements, especially by the 

 chemical action of light, or by their mass sinking into an abyss 

 formed beneath them. 



This last circumstance must have happened to one of the 

 Azores elevated in 1719, and which disappeared in 1723, leav- 

 ing in its place a depth of seventy fathoms, and to another 

 island in the same region in 1638, where there is now a 

 fathomless abyss. 



The vapour, ashes and scoria ejected from the volcanoes of 

 Mauritius and its neighbourhood, which continued through all 

 the successive periods of the deposits forming Eound Island, 

 as shewn by the sprinkling of them in each layer of the 

 sandstone, must have been dense enough to darken the sun, 

 and intercept the light of day. 



We see instances of wind driving along such clouds to a 

 great distance even in the present day. 



At Mauna Loa in J^ay 1868 a column of smoke and ashes, 

 seven and four fifths of a mile in altitude was thrown out of 

 the mountain obscuring the whole country round, save when 

 the bright spiral pillars of flame flashed upwards from the 

 mouth of the crater : and at a distance of some hundred of 

 miles at sea, it was so dense, as to prevent the taking obser- 

 vations of the sun by the captain of a vessel then at that place. 



This sight is said to have been one of the most magnificent, 

 yet most appalling ever witnessed in modern times. 



I do not believe it possible for man to have been a witness 

 of the horrors accompanying the eruptions and convulsions of 

 the early ages of this planet. 



We have here I think another proof of the Divine fore- 

 thought for man, that the greater part of these terrific con- 

 vulsions took place before the era of animal life : convulsions 



