THE EARTH. 57 



lo see fire not only break out of the bowels of the fcarth, but also 

 make itself a passage through the waters of the sea ! What can be 

 more extraordinary, or foreign to our common notions of things, 

 than to see the bottom of the sea rise up into a mountain above 

 the water, and become so firm an island as to be able to resist thts 

 violence of the greatest storms ! I know that subterraneous fires, 

 when pent in a narrow passage, are able to raise up a mass of earth as 

 large as an island : but that this should be done in so regular and ex- 

 act a manner that the water of the sea should not be able to pene- 

 trate and extinguish those fires ; that after having made so many pas- 

 sages, they should retain force enough to raise the earth ; and, in fine, 

 after having been extinguished, that the mass of earth should not fall 

 down, or sink again with its own weight, but still remain in a manner 

 suspended over the great arch below ! This is what to me seems more 

 surprising than any thing that has been related of Mount JEtna, Vesu- 

 vius, or any other volcano." 



Such are his sentiments ; however, there are few of these appear- 

 ances any way more extraordinary than those attending volcanoes and 

 earthquakes in general. We are not more to be surprised that inflam- 

 mable substances should be found beneath the bottom of the sea, than at 

 similar depths at land. These have all the force of fire giving ex- 

 pansion to air, and tending to raise the earth at the bottom of the 

 sea, till it at length heaves above water. These marine volcanoes are 

 not so frequent ; for, if we may judge of the usual procedure of nature- 

 it must very often happen, that, before the bottom of the sea is ele- 

 vated above the surface, a chasm is opened in it, and then the water 

 pressing in, extinguishes the volcano before it has time to produce its 

 effects. This extinction, however, is not effected without very great 

 resistance from the fire beneath. The water, upon dashing into the 

 cavern, is very probably at first ejected back with great violence ; and 

 thus some of those amazing water-spouts are seen, which have so often 

 astonished the mariner, and excited curiosity. But of these in their 

 place. 



Besides the production of those islands by the action of fire, there 

 are others, as was said, produced by rivers or seas carrying mud, 

 earth, and such like substances, along with their currents; and at last 

 depositing them in some particular place. At the mouths of most 

 great rivers, there are to be seen banks, thus formed by the sand and 

 mud carried down with the stream, which have rested at that place*, 

 where the force of the current is diminished by its junction with tin; 

 soa. These banks, by slow degrees, increase at the bottom of the 

 deep: the water in those places, is at first found by mariners to grow 

 more shallow ; the bank soon heaves up above the surface ; it is con- 

 tfklered, for a while, as a tract of useless and barren sand : but the 

 seeds of some of the more hardy vegetables are driven thither by the 

 wind, take root, and thus binding the sandy surface, the whole spot 

 s clothed in time with a beautiful verdure. In this manner there are 

 delightful and inhabited islands at the mouths of many rivers, particu- 

 larly the Nile, the Po, the Mississippi, the Ganges, and the Senegal. 

 There has been, in the memory of man, a beautiful and large island 

 formed in this manner, at the mouth of the river Nanquin, in China 



