306 Olservations upon the 



of which, interwoven together, of a reddish colour and full 

 of hollow bubbles, were from three to six lines in diameter. 

 In the fractures of these sprigs I found pyroxene schorls of 

 a perfect crystallization and of a deep olive colour. These 

 shootings of lava show that the lava was in complete fusion, 

 and that the sprigs were cooled and hardened the moment 

 they were separated from it. 



There was here no slow cooling which could have formed 

 these crystals, nor was there a continuous mass sufficient 

 to give birth by this means to crystalline forms. Never- 

 theless there are pyroxene schorls, the most of them even at 

 the surface of the shootings: Is this not a new }.roof that 

 these crystals were pre-existeut to the lava? M. Fleuriau 

 de Bellevue does not admit this conclusion ; but if we draw 

 our atlention to the fact, we shall find it very probable. The 

 surface of the sprigs of this singular stalactite and that of 

 the interior of the bubbles are covered with a multitude of 

 brilliant points, which are only perceived when the light 

 shines strongly on them ; when viewed with a magnifying 

 glass, they !.'irk like m..;iite panicle.' of sublimed iron. 



The following' is another very rema-kable fact, and which, 

 in order to discover it, requires all the attention with which 

 I entered upon the observation of volcanic phenomena; I 

 have already mentioned it, but it is necessary to bring it 

 again before the pub'ic. 



The branches which arc separated from a flowing lava, 

 or the lava itself when it is not abundant, are broken into 

 fragments at their extremity, which in this case has no pro- 

 gressive motion, except by the shaking of these fragments 

 pushed forwards and sidewavs bv an interior impulsion. 

 These [leaped \\\i fraonicnts preserve their inflamed state a 

 long time : this is very perceptible at night ; and in the day- 

 time it is known by their great heat, and the sulphurous 

 fumes and mephitic gases which thev exhale. These frag- 

 ments, broken from the lava itself, and which have never 

 been for one moment uninfiamed, show pyroxene schorls 

 at their surface. I am in possession of two of these frag- 

 ments, which I gathered at a place where they abound. 

 What can we reasonably object to. this great number of 

 2 facts ? 



