Magnets, attachment and repulsion of, 75.
Maxwell, 141.
Mayer, 140.
Mechanical energy changed into heat, 23.
equivalent of heat, 43.
force, 205.
instability, 155.
Mental forces, mutual correlations of, 227-236.
Mind, its correlations to natural forces, 218-227.
and body, 207, 211.
Molar force, 205.
Molecular attraction and heat, 55.
separation, 80.
Molecules, ultimate, of matter, 5.
their motions, 7.
and atoms, 51.
Motion changed into an electric current, 99.
Muscular power, 207.
Narcotic stimulants, 229.
Negative and positive electricity, 63.
Nerve power, 207.
Newton, 136, 137.
Non-couductors of electricity, 61.
Percussion, 36.
Perpetual motion, 139.
Physical force, 194.
Plants growing at night, 181
Positive and negative electricity, 63.
Protoplasm, 177.
Pulleys, their function, 30.
Radiant energy, 81.
converted into absorbed heat, 123.
promoting chemical separation, 123.
Rankine, 141.
Resinous and vitreous electricity, 63.
Rotation of earth retarded, 95.
Rumford, 39, 137.
Silver oxide readily decomposed, 58.
Solar rays, decomposition by, 59.
Sulphur, 146.
Sun—a source of high-temperature heat, 148.
Sun's heat, origin of, 150.
spots, auroras, and cyclones correlated, 98.
Tait, 141.
Temperature of dissociation, 115.
Thermo-electricity, 116.
Thermopile, 117.
Thomas Aquinas, 209.
Thomson, William and James, 140.
Tides, 146.
Tissues, decay of, 164.
Universe, its probable fate, 152
Units of heat and work, 46.
Vegetation, 176.
Velocity and energy, relation between, 16.
Virtual velocities, 34.
principle of, its history, 137.
Vital force, whence derived, 171.
Vitality, 194.
Vitreous and resinous electricity, 63.
Voltaic current, 69.
and magnetism, 72.
heating effect of, 73.
chemical effect of, 74.
Water at high level, 24.
Watt, 138.
Wild's electro-magnetic machine, 103.
Will, 194.
Work, definition of, 15.
unit of, 15.
rise of true conceptions regarding, 138.
Yeast-plant, 185.
THE END.