Whitney, Ely, the cotton gin, [436].

Wissler, Clark, culture areas, [26]; trade, [104].

World state, [493].

World war, breaks the barriers of thought, [488].

World War, iconoclastic effects of, [427].

Writing, [181].

Wyclif, John, and the English reformation, [378], [386].

Zeno, [220].

Zenophanes, [220].

Zwingli and the reformation in Switzerland, [385].