crystallized Bodies contained in Lava. 311 



cn'Stals contained in lava, when tliey have no regular form ? 

 Besides, the play of affinities cannot take place unless when 

 the molecules upon which they act are at liberty to unite 

 themselves ; which could only take place in fluids in a state 

 of perfect liquidity. This is not the case with the lavas, in 

 the heart of which, it is said, these affinities are exercised. 

 They are certainly in fusion, but it is a dull and heavy fu- 

 sion, which has no progressive motion, except upon rapid 

 declivities, or bv the successive impulse given by the matter 

 which comes out of the volcano pushing it forward and 

 driving aside those which precede it. How could the affi- 

 nities exert themselves upon such a mass? 



The burning substances thrown out by the explosions of 

 the crater, some of which are drops of compact lava, and 

 others are fragments torn from the lava in fusion, at that 

 time full of bubbles or presenting a tliveady substance, also 

 contain pyroxene schorls, which are shown throughout the 

 ^vhole of these fragments v.-hen they are exposed to tlie ero- 

 sive action of the vapours of the crater. This action is 

 sometimes carried so far as to reduce these fragments to a 

 stale of softness almost equal to that of common tlour paste; 

 and the schorls being then also perfectly well preserved, they 

 are very easily distinguished bv their black colour from this 

 yellow and sulphurous p-.ste, which on drying resumes some 

 consistency, but is easily broken. I have collected several 

 pieces in these difii:5rent states, which are at present before 

 inc. 



We cannot suppose that there had been in this a former 

 cooling for one moment, since these fragments were thrown 

 from the cauldron of the volcano at the moment even of the 

 greatest fusion of the substances it contains. 



" One of the most natural ideas which would be pre- 

 sented in order to resolve so ninnv difficulties," M. Flcuriau 

 de Bcllevnc says, *' would be to compare carefully the pro- 

 ducts of the volcanoes and the circumsiances in which they 

 arc, with the results which the large masses of fire produce, 

 by means of which we separate, dissolve, concentrate, and 

 combine the minerals, and cause them to change their I'orm." 



1 have 



