E. What is here called Tutty, is probably the sublimed floculent white oxid, or flowers of zinc.

The lime or mortar here described, appears to be the terra puzzuolana or terras, a compound of lime and oxid of iron, which forms an indestructible cement, even under water; and the remarkably light stones ejected from the volcano, and used in the construction of their vault, were probably of pumice.

"Oker is a fossil earth combined with the oxid of some metal."Ib., p. 96.