252 ®5Sr THE CRYSTALS IN LAVA5« 



of matters successively thrown up by its eruptions, the fo? 

 cus of which is beneath all the strata with which we are ac- 

 quainted. 

 Crystals in lava That the crystalline substances included in lava are for 

 foreign to it. ygigu to it : that they have been formed aateriorly in the 

 humid way in strata, which the volcanic fires have reduced 

 to fusion leaving their crystals untcuched, because those 

 fires had not sufficient intensity to fuse theoj. 

 The ■whole That we should cease to say volcanoes manifest thera- 



mountainisa gejves ou the summits of mountains, because volcanic 

 irolcano. . . . , rr-n • • i 



jnountams entire constitute volcanoes. 1 his is the reason 



>vhy new mouths frequently open in their sicjes, or at their 



base. 

 Sea water ne- That sea water is absolutely necessary, by the salts it 

 cessary to it. }jo]js jj^ solution, to excite the fern>eatations that produce 



volcanoes. 

 All other That all the strata and substances, which compose calca- 



mountainsand j-^Q^g^ schistous, or granitic mountains, and, all their varicr 

 by water. ties, as well as sandy, gypseous, and argilli^ceous hills, are 



the work of water. 

 All ancient That all the ancient volcanoes, which are nqw inland, 



volcanoes hav? \^^xq burned underneath the waters of the sea. The schists 

 burned under i • i • i i n i c • 



the sea. and granites wnicq appear around some ot them are loreiga 



to them, belonging to strata through which the eruption 

 forced a passage, and which have remained bare. They 

 would have been buried under the volcanic matter, to be 

 seen no more, if those volcanoes had been longer actiye. 

 Those which were burning at the time when the sea retired 

 from our continents ceased to burn at that period: a period 

 beyond the memory of the inhabitants of the country, 

 because there could be no inhabitants of the land round 

 those volcanoes, when it formed part of the bottom of the 

 sea. 

 Volcanic fand Among the numerous facts that prove this truth, coun^ 



between two jyj^rzari of Vicenza has furnished me with a very remark- 

 caicateoub , . ■ j ■ 



strata. able one, on his return from a tour in Ativergne, At San^ 



tourgue there is a stratum of volcanic sand, about six 

 inches thick, between two calcareous strata. After a calca- 

 reous deposition had been formed therefore on the sides of- 

 base of the volcano, an eruption must have thrown out and 



spread^ 



