— regia, xi, 182.
[Silex,] fusion of, ii, 292.
—, solubility of, xiv, 385; xli, 60.
—, gelatinous, Guillemin, xiv, 391.
—, in solution, in geodes, viii, 282.
—, —, ibid, G. Bischof, xlix, 396.
—, hydrate of, xv, 390.
— in plants, xxxiv, 27.
Siliceous buhr millstone deposits of Ohio, xxix, 142.
— —, hot water origin, xxix, 45.