—, in Rhode Island, viii, 230.
Idria quicksilver mines, xxix, 219.
Igneous action, as indicated by certain minerals in New York, L. C. Beck, xlvi, 333.
— origin of some trap rocks, B. Silliman, xvii, 119.
— — ibid, T. Cooper, iv, 205.
— theory of the earth, remarks on, W. Maclure, xvi, 351.
— — —, as connected with the secular variation of the magnetic needle, J. H. Lathrop, xxxviii, 68.
— — —, applications of, ibid, xxxix, 90.
Ignis fatuus, observations on, J. Mitchell, xvi, 246.
Iguanodon, bones of, in Mantell's Museum, xxiii, 165.