Page:Theophrastus - History of Stones - Hill (1774).djvu/105

 Places, indeed, in which Ptimices are produced, eem to tetify the Manner of their Formation; for they are principally found about the Craters of the burning Mountains. On the whole, ome Kinds of them, perhaps, may be formed by the Action of Fire on Stones of a proper Texture, and others in ome other Manner: for there are in Nature many different Ways of Production.

XXXVI. The Pumices in the Iland of Niuros eem an Intance of this,