Note 563 — MANGANESE561.

Under this appellation, writers on the art of glass-making understand a mixture of sand or siliceous earth and alkaline salts, which at the German glass-houses, where the above word is seldom heard, is called Einsatz. It appears to have been brought to us, along with the art, from Italy, where it is written at present fritta, and to be derived from fritto, which signifies something broiled or roasted. It seems to be the same word as freton, which occurs in Thomas Norton’s Poem, Crede mihi, sive Ordinale, where it however signifies a particular kind of solid glass, fused together from small fragments. This Englishman lived about the year 1477. His treatise was several times printed.