PRESIDENTIAL ADDRESS. — SECTION I. I3 



however, in these much- despised vohimes, the " Encyclojitjedia 

 Britannica." One may perhaps quote Clerk Maxwell on this 

 subject. He says : — 



" When the vortex atom is once set in motion, all its jiroperties are fixed 

 by the laws of motion of the primitive Huid. The disciple of Lucretius may 

 cut antl carve his hard, solid atoms in the hope of getting them to combine 

 into worlds ; the followers of Boscovich may imagine new laws of force 

 to meet the requirements of each new ]ihenomenon : but he who dares to 

 plant his feet in the path opened by Helndioltz and Thomson, has no such 

 resources. His primitive fluid has no other properties than motion, invariable 

 density and perfect mobility, and the method by which the motion of this 

 fluid is to be traced is by mathematical analysis. The difficulties of this 

 method are enormous, but the glory of surnn)unting them would be unique." 



In 1816 Faraday pointed out the possibility of a fourth state 

 of matter as a consequence of a transformation of gaseous matter 

 into something that would transcend it as much as a gas transcends 

 a liquid, and he thought it quite likely that some such transforma- 

 tion would occur, by which we might get a better knowledge of 

 the nature of the chemical elements. He stated that the decom- 

 position and recomposition of metal were problems which would 

 one day be solved by chemistry ; in other words, that transmutation 

 was not impossible of realisation. 



Many years ago Crookes showed that during the electrical dis- 

 charge in a vacuum tube, small j^articles were shot off from the 

 cathode with very great velocity. These particles were apparently 

 composed of matter in a different state from that of a solid or 

 liquid or a gas — Crookes considered it at that time to be ultra- 

 gaseous, or composed of matter in a " fourth " state. Can we 

 say that he was wrong ? It will be shown that, if the corpuscle 

 is not matter exactly, it may be just the connecting link between 

 ether and matter. For a long time Crookes' views as to the material 

 nature of these particles were not accepted by everyone, especially 

 by the Continental physicists ; but by this time so much experi- 

 mental evidence has been amassed that no one doubts the truth 

 of the theory, and we accept the "existence of these particles, now 

 known as corpuscles. If our theories are correct, a knowledge of 

 these corpuscles will enable us to arrive at a solution of that problem 

 which has exercised the minds of thinkers for ages, viz., the consti- 

 tution of matter itself. Now let us consider these corpuscles. 

 How are they produced and why does a study of them enable us 

 to gain some knowledge of the inner nature of matter. If a power- 

 ful electrical discharge is allowed to occur between two conductors 

 we get a bright flash of light which passes verj- quickly, the length 

 of the path of the discharge being usually short if it passes through 

 air or a gas at atmospheric pressure. If, however, the discharge 

 passes through a tube in which the pressure of the air has been 

 reduced, the length of the path becomes greater and at the same 

 time altering in character. Instead of getting a bright, short flash, 

 we have a glow. The discharge and the luminosity are limited to 

 the central parts of the tube in which the discharge is taking place, 

 and the glass itself does not become luminous. When the pressure 

 is reduced to a very small value the nature of the discharge is 

 different again. Very little luminosity is now seen in the path of 

 the discharge, but the glass tube itself is now highly luminous, 



