The cyclic tendency so obvious in Nature is not least notable in the domain of knowledge. The discovery of one era is lost in the next, only to reappear at a later day, welcomed as a triumph of modern ingenuity or science. In maps of three centuries ago the Nile is shown rising from great lakes, but in the atlases that our fathers used the lakes have vanished and a range of imaginary mountains lies like a little woolly caterpillar in the heart of Africa as the source of the Nile, only to be replaced once more in our own days by the great lakes. Dragons, after being commonplaces of ancient time, fell into undeserved contempt, their very existence denied by a sceptical generation, and have only been rescued and rehabilitated in recent years by men of science, who, ashamed to admit that they have found the fabulous monsters of faery, have disguised them in polysyllabic nomenclature of 'saurus.' The 'travellers' tales' of old Herodotus, scoffed at by the superior minds of the unimaginative Victorian era, are daily gaining acceptance; King Chedorlaomer and other worthies, who, after centuries of blameless biblical existence, were conclusively demolished by the High German Critics, have reappeared on contemporary tablets of imperishable clay unkindly disinterred by archæological explorers; and, in more mundane matters, the very latest developments of sanitary science prove to have been anticipated by a trifle of sixty centuries in the palaces of Crete. So with Alchemy. The transmutation of the base into the noble, above all of the baser metals into gold, was accepted as feasible from the earliest historic times until the seventeenth century. Then the spread of printing enabled so many votaries of the science to publish their ideas and theories that all belief in Alchemy was swept away by the flood of mystical nonsense, but now science is back on the threshold of the knowledge of transmutation. The old alchemists seem to have based their theories on the belief that all metals, and indeed all matter, contained one common element, of which the purest and most perfect form on this earth was gold. This theory was knocked on the head when scientists discovered the Atomic Theory. Proof positive was adduced that certain substances, such as gold and silver, were elements, and that elements consisted simply and solely of agglomerations of indivisible atoms, each of which possessed the characteristics of its particular element. In other words, Gold was Gold and Silver was Silver, and there was an end to it. But now the indivisible atoms are beginning to fly in pieces before the skilful and remorseless attack of modern scientists, and it will be no surprising thing if we live to see the 'elements' of our schooldays reduced to combinations of two or three Primary Elements, even if the Primordial Element, the great First Cause, is not weighed, measured, and photographed. If, then, gold and silver can be split into the same