I may mention here another feature of some interest, which I believe to have noted in the course of these experiments, though the observations do not amount to a certitude.  It appeared that under the molecular impact caused by the rapidly alternating potential the body was fused and maintained in that state at a lower temperature in a highly exhausted bulb than was the case at normal pressure and application of heat in the ordinary way—­that is, at least, judging from the quantity of the light emitted.  One of the experiments performed may be mentioned here by way of illustration.  A small piece of pumice stone was stuck on a platinum wire, and first melted to it in a gas burner.  The wire was next placed between two pieces of charcoal and a burner applied so as to produce an intense heat, sufficient to melt down the pumice stone into a small glass-like button.  The platinum wire had to be taken of sufficient thickness to prevent its melting in the fire.  While in the charcoal fire, or when held in a burner to get a better idea of the degree of heat, the button glowed with great brilliancy.  The wire with the button was then mounted in a bulb, and upon exhausting the same to a high degree, the current was turned on slowly so as to prevent the cracking of the button.  The button was heated to the point of fusion, and when it melted it did not, apparently, glow with the same brilliancy as before, and this would indicate a lower temperature.  Leaving out of consideration the observer’s possible, and even probable, error, the question is, can a body under these conditions be brought from a solid to a liquid state with evolution of less light?

When the potential of a body is rapidly alternated it is certain that the structure is jarred.  When the potential is very high, although the vibrations may be few—­say 20,000 per second—­the effect upon the structure may be considerable.  Suppose, for example, that a ruby is melted into a drop by a steady application of energy.  When it forms a drop it will emit visible and invisible waves, which will be in a definite ratio, and to the eye the drop will appear to be of a certain brilliancy.  Next, suppose we diminish to any degree we choose the energy steadily supplied, and, instead, supply energy which rises and falls according to a certain law.  Now, when the drop is formed, there will be emitted from it three different kinds of vibrations—­the ordinary visible, and two kinds of invisible waves:  that is, the ordinary dark waves of all lengths, and, in addition, waves of a well defined character.  The latter would not exist by a steady supply of the energy; still they help to jar and loosen the structure.  If this really be the case, then the ruby drop will emit relatively less visible and more invisible waves than before.  Thus it would seem that when a platinum wire, for instance, is fused by currents alternating with extreme rapidity, it emits at the point of fusion less light and more invisible radiation than it does