— — of iron glance, Mitscherlich's theory of, xxxvi, 237.
— rocks, descriptive arrangement of, G. P. Scrope, xv, 28.
— — or lavas, South America, why not crystalline, xxxi, 176.
— —, nature of, G. Bischof, xxxvi, 252.
— —, scoria of Hawaii, xvi, 348.
— —, fusibility of, G. Bischof, xxxvi, 240.
— —, still soft after crystals have formed, G. Bischof, xxxvi, 266.
— —, force required to raise, xv, 125.
— —, raised by steam, and force required, G. Bischof, xxxvi, 241.
— —, eruptions of, xxxvi, 261.