MODERK VIEWS ()N MATTER. 227 



dieted the priiieiple of the conservation of energy, and was troubling 

 physicists with the idea that the}' must overhaul their theories — a 

 thing which they ought always to be deHghted to do on good evi- 

 dence — this idea was a gratuitous absurdity and never had the slightest 

 foundation; l)ut the notion that radium was perhaps able to draw upon 

 some unknown source or store of energ}^, without itself suffering loss, 

 was a possibility which has not yet wholly disappeared from some 

 minds. Sir W. Crookes, for instance, suggested that it might some- 

 how utilize the most quickly moving atoms of air, after the fashion of 

 a Maxwell demon — a possibility that should always be borne in mind 

 as a conceivable explanation of the power of some living organisms. 

 It is much more reasonable to suppose, however, that radium and the 

 other like substances are drawing upon their own stores of internal 

 atomic energy, and thereby gradually disintegrating and falling into 

 other, and ultimateh* into more stable, forms of matter. 



Not that it is to be supposed that even these are finally and abso- 

 lutel}^ stable; these, too, are subject to radiation loss, and so must be 

 lial)le to decay, but at a vastly slower rate, perhaps not more than a 

 few hundred atoms changing and difl'using away each second — a process 

 utterly imperceptil)le to the most delicate weighing until after the lapse 

 of millions of .years, so that for all practical purposes, and for times 

 such as are dealt with in cosmic histor}^, they are permanent, even as 

 the solar system and stellar aggregates appear to us to l)e permanent. 

 Yet we know that all these systems are in reality transitory, as terres- 

 trial structures like the p3^ramids or as the mountains and the conti- 

 nents themsehes are transitory; of all these things it may ])e said that 

 in any given form they have their da}' and cease to l)e. But whereas 

 geological and astronomical contigurations pass through their phases 

 in a time to })e reckoned in millions of years, the active life of a solar 

 system covering perhaps no very long period, it is probal)le that tbe 

 changes we have begun to suspect in the foundation stones of the uni- 

 verse, the more stable elemental atoms themselves, nuist require a period 

 to be expressed only by millions of millions of centuries. For in such 

 a time as this, at the rate of a hundred atoms per second, a bare kilo- 

 gram — a couple of pounds only — of matter, even of heavy matter, 

 would have drifted away, 'not so nuich indeed — a couple of ounces 

 more likely. And yet this period is a million times the estimated age 

 of the earth. 



16. If we allow ourselves to speculate on the strength of the slender 

 experimental evidence as yet forthcoming, instead of waiting, as to be 

 wise we nuist wait, for contirmation and thorough examination of the 

 facts, we should say that the whole of existing matter appears liable 

 to processes of change, and in lliut sense to he a ti'ansient phenomenon. 



Somehow, we might conjecture, by some means at present unknown, 

 it takes its rise: electrons of opposite sign crystallizing or falling 

 together, perhaps at first into a manifestly unstable form; these forms 



