Les Atomes

IN these days, when such notable and exten sive advances are being made in nearly all fields of physical research, it is extremely desir able that the results which mutually bear upon one another should from time to time be collected together and recorded in more or less popular language. If, in addition, a leading expert can be persuaded to undertake the record, the event of its publication is still more to be welcomed. Prof. Perrin is the ideal author for a book on atoms and molecules. He has virtually made them visible and established their reality, and it is scarcely too much to say that his work on Broxvnian movement is the most notable of recent physical researches.Les Atomes.By Prof. Jean Perrin. Pp. xvi + 296. (Paris: Félix Alcan, 1913.) Price 3.50 francs.