DOMAIN XII. VOLCANIC. 



by hemispherical protuberances and con- 

 cavities, but that the corners of one joint 

 rise into what may be called triangular 

 mortices, nicely adapted to receive the 

 next joint, which appears as if cut for that 

 purpose*. Patrin showed me, at Paris, 

 and has engraved in his mineralogy, speci- 

 mens of Siberian emerald, with similar pro- 

 tuberances and concavities ; the former 

 sometimes admitting of being detached 

 when it assumes the form of an irregular 

 oval. But no one has doubted that these 

 emeralds are crystallised by water; and 

 Patrin makes the curious observation, that 

 when they are broken in the mine, they 

 are soft as an apple, " and the two frac- 

 tures are covered with a fluid of an unctu- 

 ous appearance, and penetrating smell, 

 which evaporated quicker than a drop of 

 ether :"-f- but exposure to the air for a few 



* Da Costa, however, had observed and engraved the same ap- 

 pearances, in 1757. See his Fossils, p. 256, and the plate. 



\- Min. ii. 33. From this and other circumstances, detailed in 

 various parts of his work, Patrin argues for a kind of mineral life. 

 He might have rather said that God fills all space. 



Mens agitat molem, et inaguo se corpore miscet. 



