Part 18 (1/2)

Plasticity of organic nature, 216.

Plateau, his law of free liquid equilibrium, 9; his method of getting rid of the effects of gravity, 4.

Plates of oil, thin, 6.

Plato, 347, 371.

Plautus, 347.

Playfair, 138.

Pleasant effects, cause of, 94 et seq.

Pliny, 349.

Poetry and science, 30, 31, 351.

Poinsot, on the foundations of mechanics, 152 et seq.

Polarisation, 91; abstractly described by Newton, 242.

Politics, Chinese speak with unwillingness of, 374.

Pollak, 299.

Polyp plant, humanity likened to a, 235.

Pompeii, 234; art in, 80.

Popper J., 172, 216.

Potential, social, 15; electrical, 121 et seq.; measurement of, 126; fall of, 177; swarm of notions in the idea of, 197; its wide scope, 250.

Pottery, invention of, 263.

Prediction, 221 et seq.

Prejudice, the function, power, and dangers of, 232-233.

Preparatory schools, the defects of the German, 346-347; what they should teach, 364 et seq.

Pressure of a stone or of a magnet, will compared to, 14; also 157.

Primitive acts of knowledge the foundation of scientific thought, 190.

Problem, nature of a, 223.

Problems which are wrongly formulated, 308.

Process, Carnot's, 161 et seq.

Projectiles, the effects of the impact of, 310, 327-328; seen with the naked eye, 311, 317; measuring the velocity of, 332; photography of, 309-337.

p.r.o.ny's brake, 132.

Proof, nature of, 284.

Prophesying events, 220 et seq.

Psalms, quotation from the, 89.

Pseudoscope, Wheatstone's, 96.

Psychology, preceded by astronomy, 90; how reached, 91 et seq.; helps physical science, 104; its method the same as that of physics, 207 et seq.

Pully arrangement, ill.u.s.trating principle of least superficial area, 12-13.

Purkinje, 284, 285, 291, 299.

Purposes, the acts of nature compared to, 14-15; nature pursues no, 66.

Puzzle-lock, a, 26.

Puzzles, 277.

Pyramid of oil, 6.

Pythagoras, his discovery of the laws of harmony, 32, 259.

Quality of tones, 36.

Quant.i.tative investigation, the goal of, 180.

Quant.i.ty of electricity, 111, 118, 119, 167-170, 173; of heat, 166, 167-171, 174, 177, 244; of motion, 184.

Quests made of the inquirer, not by him, 30.

QuAtelet, 15, footnote.

Rabelais, 283.

Raindrop, form of, 3.

Rameau, 34.

Reaction and action, principle of, 191.

Reactions, disclosure of the connexion of, 270 et seq.

Realgymnasien, 365.