Epidote of Franconia, N. H., account of, _C. U. Shepard_, xviii, 129.^f ----, crystals from Haddam, Ct., xlvi, 380.^f ----, localities of, in Canada, viii, 62. ----, ----, in N. Carolina, v, 262. ----, ----, in Connecticut, i, 354; ii, 240; vi, 223; viii, 258; xii, 170; xviii, 361. ----, ----, in Delaware, xiv, 11. ----, ----, Massachusetts, i, 114; iii, 364; vi, 223; vii, 253; viii, 235; ix, 43. ----, ----, New Hampshire, ii, 241; vi, 245; viii, 235; xviii, 129. ----, ----, in New Jersey, v, 243. ----, ----, in New York, ii, 241; iv, 47; vii, 58; ix, 41. ----, ----, in Pennsylvania, viii, 238; xiv, 6. ----, ----, in Rhode Island, iv, 285; x, 10. ----, ----, in Vermont, vii, 58; xvii, 354. Epistilbite and Heulandite, identity of, xiii, 185. Equations, differential of the second order, integration of, _T. Strong_, xlii, 273. ---- of the fourth degree, on the resolution of, xviii, 276. ---- of the third and fourth degree, method of resolving, _A. C. Twining_, ix, 86. Equilibrium between living and dead forces, condition of, _R. H. Fauntleroy_, xlvii, 241.^f Equinoxes, precession of, vii, 323^f; viii, 132, 139.^f Equiseta, N. American, _A. Braun's_ monograph, with additions by _G. Engelmann_, xlvi, 81. Equisetum arvense, xlvi, 83. ---- boreale, xlvi, 90. ---- eburneum, xlvi, 84. ---- giganteum, xlvi, 91. ---- hyemale, xlvi, 89. ---- lævigatum, xlvi, 87. ---- limosum, xlvi, 86. ---- palustre, xlvi, 85. ---- pratense, xlvi, 85. ---- robustum, xlvi, 88. ---- scirpoides, xlvi, 91. ---- sylvaticum, xlvi, 84. ---- variegatum, xlvi, 90. Equivalents, chemical, _Wollaston's_ scale of, xvi, 371. ----, ----, ----, improved, _L. C. Beck_ and _J. Henry_, xiv, 202. ----, ----, circular scale of, _J. Finch_, xviii, 196. Eremite, a new mineral, _C. U. Shepard_, xxxii, 341.^f ----, crystallographic examination of, _J. D. Dana_, xxxiii, 70.^f ----, identical with monazite, _J. D. Dana_, xlv, 402.^f Ergot of rye, _W. Tully, M. D._, ii, 45. ----, remarks on, xii, 398. ----, on the origin of, _M. Field_, ix, 359. Erie canal, tolls on, x, 398.