Note 91 — ZINC.

We read in Observations sur la Physique, vi. p. 255, that for many years tutia has been collected and sold in the bishopric of Liege. Lehmann endeavours to show that it was made by the Jews in Poland. Novi Comment. Acad. Petrop. xii. p. 381. As the use of tutia [which is an impure oxide of zinc found in the chimneys of the furnaces in which zinc-ores are roasted, or in which zinciferous lead-ores are smelted] has been almost abandoned, because physicians prefer pure flowers of zinc, and because those who make pinchbeck employ purified zinc, it is probable that this substance will soon be entirely neglected.