274 CLAY GENUS. Although it has been ufually clafled among the volcanic products, on account of its fuppofed igneous origin, we muft confefs that in Hungary at lead it is- demonftrably of aquatic formation j and we may on pretty fure grounds confider that of Lipari and An- dernach as a portion of one of thofe great and uni" verfal formations which have been depofited from a date of folution in water. In the Geognofie will be given a full ftatement of the interefting faffs which render this opinion probable. Geographic Situation. It is found in the Lipari Iflands, Hungary, banks of the Rhine between Andernach and Coblentz, Iceland ? and it has been obferved particularly beautiful in the I Hand of Santorine in the Hellefpontic Archipelago. Ufes. It is ufed for polifhing ftones, metals, glafs a nd ivory; alfo for preparing parchment. seventh
