195.

Chamberlin and Salisbury, the Laramide range, 121.

Clarke, F. W., estimate of mass of sediments, 9; age of Earth by
sodium collection, 14; average composition of sedimentary and
igneous rocks, 42; on average composition of the crust, 126;
solvent denudation of the continents, 17, 40.

Claus, protoplasm the test of the cell, 67; abortion of useless
organs, 69.

Coefficient of friction, definition of, 262; deduction of, from
angle of friction, 263; abnormal values on ice, 261-265, 282; for
various substances, 265.

Continental areas, movements of, 144.

Cornil and Babes, size of spores, 98.

Croll, James, dawn of evolution, 301.

Crust of the Earth, average composition of, 126; depth of
softening in, 128.

Curie, definition of the, 256.

D.

Dana, on mountain building, 120.

Dawson, reduction of surface represented by Laramide range, 123.

Deccan traps, 137

_deferlement_, theory of, 155; explanation of, 155 _et seq._;
temperature involved in, 156.

Deimos, dimensions of, 177; orbit of, 577.

De Lapparent, exotic nature of the Prealpes, 150.

De Montessus and the association of earthquakes with
geosynclines, 142.

Denudation as affected by continental elevation, 17; factors
promoting, 30 _et seg._; relative activity in mountains and on
plains, 35-40; solvent, by the sea, 40; the sodium index of,
46-50; thickness of rock-layer removed from the land, 51.

De Quincy, System of the Heavens, 200.

Dewar, Sir James, latent image formed at low temperatures, 202.

Dixon, H. H., and AGnadance of Life, 60.

Double canals, formation by attraction of a satellite, 585-187.

Douglass, A. E., observations on Mars, 167.

Dravidian Era of India, 135.

E.

Earth, early history of, 3, 4; dimensions of, relative to surface
features, 117.

Earth's age determined by thickness of sediments, 5; determined
by mass of the sediments, 7; determined by sodium in the ocean,
12; determined by radioactive transformations, 19; significance
of, 2.

Earthquakes associated with geosynclincs, 142.

Efficiency, tendency to maximum, in organisms, 113, 114.

Elements, probable wide diffusion of rare, 230; rarity of
radioactive, 241.

Elster and Geitel, photo-electric activity and absorption, 207;
photo-electric properties of gelatin, 212; Emanation of radium,
therapeutic use of, 256-259; advantages of, in medicine, 256;
volume of, 257; how obtained, 257; use of, in needles, 258.

Equilibrium amount, meaning