„ probable origin of, 17 Compound radicals, argument from, 95 Condensation in relation to nebulæ, 27 „ the last condition of a nebula, 30 Cosmical dust and “fire-mist,” 81, 102 Crookes, Mr. W., on the pre-nebular condition of matter, 90-98 „ on _protyle_, 96 61 Cygni, motion of, 16 Darwin, Mr. Charles, on geological time, 67 Denudation, age of the globe as represented by, 63, 64 „ average rate of whole globe, 44 „ evidence from faults as to rate of, 53 „ Dr. A. Geikie on rate of, 41 „ glacial epochs in relation to, 46, 47 „ in Colorado, 58 „ in past ages not much greater than at present, 44 „ method employed to estimate its rate, 39, 47 „ Mr. A. R. Wallace’s method of estimating its rate, 51 „ of Bristol coal-fields, 59 „ of Mississippi basin, Sir Charles Lyell on, 44 „ of Pendle Range, 60 „ of Pentlands, 59 „ of river basins, 41 „ of South of Scotland, 55 „ of Wales, 59 „ Prof. Haughton’s method of estimating its rate, 50 „ Rotation of the earth in relation to, 46 „ the direct method of estimating its rate, 52 „ time required to effect the amount of, 63 Dewar and Liveing on dissociation of chemical elements, 83 Dissociation of chemical elements, Dr. T. Sterry Hunt on, 82, 85 „ of chemical elements, M. Berthelot on, 83 „ of chemical elements, M. Deville on, 83 „ of chemical elements, Mr. Lockyer on, 82 „ of chemical elements, Profs. Liveing and Dewar on, 83 „ of chemical elements, Prof. Schuster on, 83 „ of chemical elements, Sir B. Brodie on, 82, 84 „ Dumas, M., on essential unity of matter, 83 Earth’s crust, argument from, 93 „ rotation, its influence on denudation, 46 Emmons, Mr. S. F., on a fault in Aqui Range, 58 Energy existing as motion of stellar masses, 3 „ transformed by collision, 3 Evolution, can it be traced back to a first condition? 110 „ evidence of, from the grouping of the stars, 81 „ from smaller to larger aggregates of matter, 81 „ of matter, 107 „ of the chemical elements, 80, 107 Faults, evidence of rate of denudation from, 53 „ examples of, 54-60 „ “Grand Wash,” Colorado, 58 „ in East Tennessee, 58 „ in Strathmore, 55 Faye, M., on origin of comets, 17 Gaseous condition essential to the nebular hypothesis, 25 „ state, second condition of a nebula, 24 Geikie, Dr. A., on area of the globe, 48 „ on denudation of the Pentlands, 59 „ on examples of enormous faults, 55 „ on rate of denudation, 41 Geological epochs of past ages, misconceptions regarding, 49 Geological time, Mr. A. R. Wallace on, 65 „ time, Mr. Charles Darwin on, 66 „ time, Prof. Haeckel on, 67 „ time, Prof. Huxley on, 65, 66