The world to the human interpreter appears as a paradox of complexes. Scientific progress, during late years, has not been along the lines of the least resistance. One who has to do with the problems of nature is fascinated by the difficulties. Lord Rayleigh attached this motto to his recently issued, but already famous, “Collected Papers:” “The works of the Lord are great Sought out of all them that have pleasure therein.” To be sure, the gratification of overcoming obstacles is often the only compensation. Science has a wide range in the size and nature of the things with which it deals. With the microscope, it enlarges for vision the unseen world of bacterial life; with the telescope it draws the celestial bodies near and interrogates them with the spectroscope; it drags the lifeless element from the inanimate world, curiously plays with it and then puts it to man’s use, while seeking his origin and forcing him ever to show cause for his existence and right to question. Much of the very recent work in physical science has distinct leanings towards metaphysics. It is scarcely to be wondered at, when the experimental data obtained appear to question tenets which devotees have become accustomed to regard as immutable. Facts are stubborn, however. When they cause the giving away of the least portion of the boundaries of our cherished systems, the imagination is unchained. The discovery and development of our knowledge of the wonderful phenomena of radio-activity, about which much that is true and more that is false have appeared in reputable journals of a not remote date, ensample the groping of our restlessness. These marvels, according to those who have worked with them most and whose opinions deserve the first consideration, spontaneously and continuously give out energy appreciable to the senses. Where does this energy come from? Where does it go? One mudsill of science is the law of the conservation of energy. This division of science has a host of investigators busy with the problem of sustaining this fundamental. The harvest, which is not all grain but contains some tares, indicates that substances, which we have been pleased to regard as elemental constituents of nature, undergo voluntary alterations. Some appear to be breaking down into simpler matter, while others are building up. This virtually carries us back to the days of the alchemist. It is a long story, which may not be related here, the deep-seated belief of most chemists in the unity, hence transmutation, of the elements. It is a far cry to its accomplishment, however. We need not go back to the time of the black-art for other examples of efforts to transform one element into another. Victor Meyer sought to build up thallium shortly after Crookes found it. Winkler dissipated Fittica’s transformation of phosphorus to arsenic. So chemists will be busy asking questions of Ramsay’s formation of a body like lead, through the agency of penetrating rays of radium.