In these radioactive elements we have come upon sources of energy such as was never dreamed of in our philosophy.  The most striking peculiarity of radium is that it is always a little warmer than its surroundings, no matter how warm these may be.  Slowly, spontaneously and continuously, it decomposes and we know no way of hastening or of checking it.  Whether it is cooled in liquefied air or heated to its melting point the change goes on just the same.  An ounce of radium salt will give out enough heat in one hour to melt an ounce of ice and in the next hour will raise this water to the boiling point, and so on again and again without cessation for years, a fire without fuel, a realization of the philosopher’s lamp that the alchemists sought in vain.  The total energy so emitted is millions of times greater than that produced by any chemical combination such as the union of oxygen and hydrogen to form water.  From the heavy white salt there is continually rising a faint fire-mist like the will-o’-the-wisp over a swamp.  This gas is known as the emanation or niton, “the shining one.”  A pound of niton would give off energy at the rate of 23,000 horsepower; fine stuff to run a steamer, one would think, but we must remember that it does not last.  By the sixth day the power would have fallen off by half.  Besides, no one would dare to serve as engineer, for the radiation will rot away the flesh of a living man who comes near it, causing gnawing ulcers or curing them.  It will not only break down the complex and delicate molecules of organic matter but will attack the atom itself, changing, it is believed, one element into another, again the fulfilment of a dream of the alchemists.  And its rays, unseen and unfelt by us, are yet strong enough to penetrate an armorplate and photograph what is behind it.

But radium is not the most mysterious of the elements but the least so.  It is giving out the secret that the other elements have kept.  It suggests to us that all the other elements in proportion to their weight have concealed within them similar stores of energy.  Astronomers have long dazzled our imaginations by calculating the horsepower of the world, making us feel cheap in talking about our steam engines and dynamos when a minutest fraction of the waste dynamic energy of the solar system would make us all as rich as millionaires.  But the heavenly bodies are too big for us to utilize in this practical fashion.

And now the chemists have become as exasperating as the astronomers, for they give us a glimpse of incalculable wealth in the meanest substance.  For wealth is measured by the available energy of the world, and if a few ounces of anything would drive an engine or manufacture nitrogenous fertilizer from the air all our troubles would be over.  Kipling in his sketch, “With the Night Mail,” and Wells in his novel, “The World Set Free,” stretched their imaginations in trying to tell us what it would mean to have command of this power, but they are a little hazy in their descriptions of the machinery by which it is utilized.  The atom is as much beyond our reach as the moon.  We cannot rob its vault of the treasure.