The rare gases recently discovered in the atmosphere, helium, neon, argon, krypton, xenon, and the unknown members of that group, certain to be found--have these zero gases, as they are called, been sought for in man? Hitherto their story is a blank, as it is impossible to unite them chemically with any element; but they constitute one per cent. of the mechanical mixture of gases which we breathe. What are they doing, then, in the air? Nitrogen alone is a sufficient diluent of the necessary oxygen. Are these rare gases purposeless? I am intensely curious about them. Are there outcasts also among the elements? Are these gases dead elements? One of them, helium, is a transmuted emanation of radium. Is it the ghost of radium? Nitrogen, with which they are found mechanically mingled, is the element of fermentation and decay. One feels upon the brink of a notable discovery. These dead gases, these ghosts of elements herding with the vapour of dissolution, nitrogen, cannot be entirely ineffective. I hazard this poetical suggestion:--It is the presence of these incommunicable elements that maintains the mechanical mixture of the oxygen and the nitrogen of the air: were their ghostly frontier eliminated, the two main members of the atmosphere would unite chemically, forming protoxide of nitrogen, which is laughing gas. Great Pan! How close we are to that rare old fantasy, that the crack of doom will be a universal shout of laughter! The names, affinities and energies of the elements of which man consists should be more secure in every memory than the alphabet and the multiplication table. This is a great part of my immorality, that, instead of a myth, children should be told, as soon as they begin to express their wonder, that they consist of oxygen, hydrogen, nitrogen, carbon, calcium, kalium, natrium, sulphur, phosphorus, iron, magnesium, silicon; that the principal human elements are also the principal constituents of the whole Universe, and that all the elements are forms of one substance. They should also be shown experimentally the qualities and properties of these elements; and gradually, instead of catechisms and the grammars of dead languages, obtain a knowledge of the poetry of evolution: a poetry that does not require to be taught or learnt; that requires only to be told and shown to be known, welcomed, and remembered, because it is already subconscious in the Matter of which we consist. Thus a child would know at once that there has been no philosophy, no religion, no literature hitherto; that there is nothing for him to learn; that every one must make for himself his own philosophy, religion, literature. All that chemists, astronomers, physicists, biologists, have discovered and suggested; all science and all its speculations--these things that do not require to be learnt, but only require to be shown to be known and delighted in, the child would soon furnish himself with; just as he would light-heartedly