driven from the negative pole meet them and render them visible. According to J. J. Thomson the mass of an electron is about the- I/ 700th part of that of the hydrogen atom, and as these masses start from the negative pole in a vacuum tube with a velocity of the order of half that of light, it is easy to see that their heating, phosphorescent, and mechanical power must be stupendous.
The basis of the Electron, as I foreshadowed in 1879 in the case of Radiant Matter, is probably the same in all cases the Protyle* from which the chemical atoms were assumed to be formed.
On the two-fluid theory, the electrons constitute free negative elec- tricity, and the rest of the chemical atom is charged positively, although a free positive electron is not known. It seems to me simpler to use the original one-fluid theory of Franklin, and to say that the electron is the atom or unit of electricity.! Then a so-called
crowd, we shall notice that the throng on the footway is not uniformly distributed, but is made up of knots we might almost say blocks interrupted by spaces which are comparatively open, we may easily conceive in what manner these knots or groups are formed : some few persons walking rather more slowly than the average rate slightly retard the movements of others, whether travelling in the same or in an opposite direction. Thus a temporary obstruction is created. The passengers behind catch up to the block and increase it, and those in front, passing on unchecked at their former rate, leave a comparatively vacant space. If a crowd is moving all in the same direction, the formation of these groups becomes more distinct. Hence mere differences in speed suffice to resolve a' multitude of passengers into alternating gaps and knots. Instead of observing moving men and women, suppose we experiment on little particles of some substance, such as sand. If we mix the particles with water in a horizontal tube and set them in rhythmical agitation, we shall see very similar results, the powder sorting itself with regu- larity into alternate heaps and blank spaces. If we pass to yet more minute substances, we observe the behaviour of the molecules of a rarefied gas when sub- mitted to an induction current. The molecules here are free, of course, from any caprice, and simply follow the law I seek to illustrate, and though originally in a state of rampant disorder, yet under the influence of the electric rhythm, they arrange themselves into well-defined groups or stratifications." ' Journ. of the Inst. Elect. Engineers,' vol. 20, p. 10.
- ' Eeport of the Fifty-sixth Meeting of the British Association,' Birmingham,
1886, p. 568 Address to the Chemical Section.
t "The theory of definite electrolytical or electro-chemical action appears to me to touch immediately upon the absolute quantity of electricity or electric power belonging to different bodies. . . . And when comes the fact that the elec- tricity which we appear to be capable of loosening from its habitation for a while, and conveying from place to place, whilst it retains its chemical force, can be measured out and being so measured, is found to be as definite in. -its action as anv of thoseporlions which, remaining associated with the particles of matter, give them their chemical relation ; we seem to have found the link which connects the pro- portion of that we have evolved to the proportion of that belonging to the particles in their natural state." Faraday's ' Experimental Kesearches in Electricity,' par. 852.
" The equivalent weights of bodies are simply those quantities of them which contain equal quantities of electricity ; ... it being the ELECTRICITY which
