THE BORDERLAND OF CHEMISTRY AND ELECTRICITY. 
223 
oscillations which give rise to visible undulations, and hence 
phosphorescent light. This really means that the bombardment 
of a substance makes the molecules and atoms of that substance 
undulate—hence light. 
First, if glass, mica, or iceland-spar be placed between different 
forms of lime and a source of light such as the spark of a coil, 
with a Leyden jar in circuit, the effect of heating is to intensify 
the phosphorescence to a blue colour. It is possible to make a 
specimen of lime give an orange glow in a low vacuum, while a 
portion of the same specimen is exhibiting a blue glow in a high 
vacuum with the same source of light. 
Under the vigorous bombardment of an electrical discharge of 
radiant matter, the temperature of the substance bombarded 
rises, and in some cases this leads to an increase of the brilliancy 
of the glow, in others the complete absence of phosphorescence. 
This seems to depend upon the hypothesis that heat endows some 
molecules with such freedom as to render them uninsulated— 
hence absence of phosphorescence. 
The flame of coal gas burnt iu a Bunsen burner will excite 
phosphorescence in many specimens of lime ; a jet of unlighted 
coal gas allowed to play over warm porous lime produces a slight 
phosphorescence visible in a dark room. Experiments with many 
substances used in a similar way to the mantles of the incandes¬ 
cent gas lights indicate that in addition to the ordinary heating 
effect there is a phosphorescent effect, which probably produces 
the ordinary hot stage. This phosphorescence can be seen if the 
mantles are introduced in a tube and treated with an electrical 
discharge in high vacuum. The attempt has been made to 
connect the phenomena of phosphorescence with a view to show¬ 
ing them to be one without a likeness in kind. It is possible then 
that the following typical examples of the various phenomena 
which are described as phosphorescent phenomena are similar in 
their kind—the glow of phosphorus, the fluorescence of quinine, 
the sparkling of heated chlorophane, the luminosity of Ballman's 
paint, the light from lime in a vacuum tube, the glowing of 
barium platinuo cyanide under the influence of the f X J rays.” 
An electric current discharge in a vacuum must have some material 
molecules or atoms as a conveying medium. Force cannot possibly 
exist without material. If you could imagine such a thing as a ghost, 
and could really see it, it must have some material substance, but it is 
only imagination, and is the action of an over-wrought or over-worked 
brain. 
Electrical force is everywhere. Our world is surrounded by it. 
We live in an electric sea ! And it is visibly illustrated by the Aurora 
Borealis. The violent wind is very largely due to electric action. 
On allowing the electric discharge in this tube to bombard the 
calcined fel spar contained in it, it, as you see, exhibits a bright 
