Posidonius on the Ligyran field of stones, 115, 116.

Pouilet on the actual source of atmospheric electricity, 335.

Prejudices against science, how originated, 38; against the study of the exact sciences, why fallacious, 40-52.

Prichard, his physical history of Mankind, 352.

Pseudo-Plato, 54.

Psychrometer, 332, 338.

Pythagoras, first employed the word Cosmos in its modern sense, 69.

Pythagoreans, their study of the heavenly bodies, 65; doctrine on comets, 103.

Quarterly Review, article on Terrestrial Magnetism, 192.

Quetelet on aerolites, 114; their periodic return in August, 125.