Obs. [a. It. tarso.] A white siliceous stone found in Italy, formerly used in glass-making.
1662. Merrett, trans. Neri’s Art of Glass, viii. Tarso … makes … fairer glass than any sand that is in Tuscany.
1712. trans. Pomet’s Hist. Drugs, I. 105. Beat … finely and searse your Tarso, Crystal, &c.
1799. G. Smith, Laboratory, I. 171. The fluxes used in the other are salts, or arsenic, and the body consists of tarso, white river pebbles, and such stones.
