Poison-gas, [413]
Poitiers, [432]
Poitiers, battle of, [253], [259]
Poland, [288], [327], [353], [434]
Political experiment, age of, [318] et seq.
Political ideas, development of, [370] et seq.
Political science, founder of, [144]
Political worship, [412]
Polo, Marco, [299-300]