THE MYSTERY OF MATTER. 193 



the atom of any element are exactly similar in every respect to 

 each other, and to the corpuscles in the atom of any other 

 element, so that the fundamental basis of all matter is the same. 

 The special radio-active elements, radium, uraniimi, etc., have 

 the largest and most complex atoms, and Rutherford considers 

 it probable that they are made up of sub-atoms identical with 

 the atom of helium, and that one of these sub-atoms is expelled 

 as an a particle at nearly every radio-active change. These sub- 

 atoms or a particles within the radium atom are in continuous 

 very rapid movement, and when a stage of instability is reached 

 one of them is expelled from the atom with the velocity which it 

 possessed in its atomic orbit. He also thinks it possible that 

 hydrogen as well as helium may prove to be one of the more 

 elementary units of which the heavier atoms are built up. 

 Professor J. J. Thomson considers that the cause of the 

 disintegration of the atoms of radium is the loss of energy by 

 radiation from the atom. 



We see, then, that the atom, far from being simple and 

 indivisible, is really a very complicated structure. And as both 

 the a and jB particles are expelled from it with such tremendous 

 force, we can understand what inconceivable stores of energy are 

 locked up in the atom. And the excessively tiny corpuscles 

 which compose it are really the basis of everything. The various 

 forms of matter which occur throughout the Universe, solid, 

 liquid, or gaseous, organic and inorganic, are all composed and 

 built up of these inconceivably minute corpuscles. The enormous 

 energy with which the corpuscles are endowed one would think 

 must have had a beginning, and in process of time must come to 

 an end. Whether these tiny bodies are indeed material specks, 

 and possess inherent mass, or whether they are really separated 

 portions of the ether, and their apparent mass is simply due to 

 the inconceivable energy with which they are gifted, is perhaps 

 an open question, though I incline to the latter view. But it is 

 absolutely certain that energy is their all-important characteristic; 

 and without energy matter as such would cease to exist. And 

 we have seen that the atoms of matter are not permanent, but 

 that some of them at any rate are constantly undergoing change : 

 each change being attended by an emission of energy. And we 

 know that the energy of the Universe is being slowly dissipated 

 into space. So that matter on the whole must be continually 

 losing energy. As at some remote period in the far-off aeons 

 past it had a beginning, so perhaps untold ages hence, not only 

 all material things, but matter itself as such, unless it be re- 

 energised, must finally come to an end. 



