JUST as the leaves of our deciduous plants fade away in autumn, and in winter perish, so do our science books have their autumn and their winter. They cannot live long under a regime which changes with the fleeting years. The publisher's spring-time brings forth an array of fresh books, but none are more welcome than some of the older and familiar forms revitalised and newly adapted to the change of environment. The reviewer has therefore a pleasing task in introducing the new editions of the above-named books to readers of NATURE, and this the more because each book is a familiar friend to chemists the world over. (1) A Treatise on Chemistry. By H. E. Roscoe C. Schorlemmer. Vol., ii., The Metals. New edition completely revised by the Rt. Hon. Sir Henry Roscoe and others. Pp. xvi + 1470. (London: Macmillan and Co., Ltd., 1913.) Price 30s. net. (2) A Dictionary of Applied Chemistry. By Sir Edward Thorpe. Assisted by Eminent Contributors. Revised and enlarged edition. In five volumes. Vol. v., Pp. viii + 830. (London: Longmans, Green and Co., 1913.) Price 45s. net.