Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/379

Rh and appeared to me larger and more numerous in the grey compact variety, than in the reddish. I observed similar globules in one of the varieties of bardiglione, consisting of small blue laminæ, from Vulpino.

When pieces of the rock of Arbonne have been boiled a certain time in water, to free them from the sea-salt they contain, they become porous, but very irregularly so; and thus shew, that the sea-salt is distributed unequally, and chiefly in small masses.

M. l'Abbé Haüy, in his Tableau Comparatif, gives the name of epigène, agreeably to its Greek etymology, to every transition of one mineral to another.

The mention which he makes of this variety of bardiglione, from which alone I am acquainted with it, is in consequence of a specimen presented to him by M. Cordier, in which one part of the substance is in the state of lamellar bardiglione, while the other is in that of compact gypsum. To the gypsum of this specimen M. Haüy gives the name of bardiglione epigène, because, in his opinion, its formation has taken place from an action exerted on the lamellar bardiglione itself, subsequent to its production; which action, from what he says p. 141, was effected by the introduction of water into its interior: whence, he adds, the substance of the bardiglione has lost part of its hardness, and its texture has become looser. He further states, that according to an observation communicated to him by M. Hassenfratz, there are at Pesai, whence this specimen came, galleries carried through the bardiglione, the outward part of which, being penetrated by moisture, has experienced a considerable enlargement.