— in coal-gas retorts, vii, 380.
—, formed by pressure, xlix, 227.
—, fusion of, by galvanism, vi, 341.
— of Sturbridge, Mass., xviii, 377.
— of Worcester, Mass., probable age of, C. Lyell, xlvii, 214.
— of Wake, N. Carolina, notice of, D. Olmsted, xiv, 243.
—, mode of working mine of, at Borrowdale, xxxi, 177.
— of Ticonderoga, vi, 178.
— at Mount Dunderberg, N. Y., v, 29.
—, for chronometers instead of oil, xviii, 179.