Confronting these reflections with the laboratory experiment we have cited at page 228, we see that they are very fully confirmed by it; perhaps it would be more true to say that they were originated by it. When the current of electricity was first turned into the glass cylinder, no result was perceived. This must undoubtedly be construed into showing that the light in the cylinder, passing through it from side to side, was more powerful than the diffused light of the electricity passing through it from end to end; which was the reason why there was no result. By diffused, we mean that the electricity, turned into the cylinder through a thin wire, would immediately spread out over the whole of its width (or cross section) and thus very much weaken its light-giving power. When exhaustion had proceeded to a sufficient extent to produce the soft tremulous light, we can only conceive that the transverse light had decreased so far that the diffused light of the electricity, passing longitudinally, had begun to balance it, which caused the tremulous appearance on account of the one beginning to disappear and the other to take its place. And when the light extended through the whole length of the cylinder and the phenomena were reversed; and when the light died away altogether, when the vacuum became sufficiently pronounced; we can only believe that there was no light at all in it; neither natural light passing through it transversely, nor light of electricity passing longitudinally. Should any one object to this demonstration, as we may call it, we refer him to the quotation, made at page 229, from Professor Balfour Stewart's "Elementary Physics," and ask him, How could there be dark zones in a tube, through which light ought to pass freely from side to side? The thing appears to be tremendously absurd. There were dark streaks in the tube and other streaks of gas, or vapour of some kind at very low pressures (see also quotation from Professor Tait at page 232) that were lighted up to some extent by the current of electricity, but even these died away. We do not pretend to impugn the idea that the stratification of light and dark zones depended upon the nature of the substances in the tube, we only want to insist that the substances left in it were so extremely rare that electricity could not pass freely through it longitudinally, nor daylight transversely, else there could have been no dark zones in it; and that even the ether was in such small force that it could not perform the carrying duties assigned to it.