EVOLUTION THE MASTER-KEY 



withstood the test of the forty most vigorous 

 years in the intellectual life of mankind is that 

 entitled "The Indestructibility of Matter." But 

 it is impossible merely to assert that the conserva- 

 tion of matter is no longer accredited by mod- 

 ern physicists, without further discussion of this 

 "law," which has held sway in men's minds for a 

 century a reign coextensive, more or less, with 

 that of the indivisible atoms of Dalton. The as- 

 sertion of the conservation of matter which we 

 really owe to the great Lavoisier, aristocrat and 

 chemist, not spared by the unrighteous excesses 

 of a most righteous revolution and the assertion 

 of the integrity of the atom are obviously com- 

 plementary or identical. It is radium the revealer 

 that has caused the supersession of both. 



Of course, the law of the conservation of matter 

 still holds for the ordinary purposes of the chemist. 

 If you weigh and then burn a candle in suitable 

 conditions, you can show that nothing was lost in 

 the process the resultant gases contain all that 

 was in the candle. But the chief discovery of the 

 twentieth century hitherto is a confirmation of 

 the central dogma of First Principles as applying 

 even to the "foundation-stones of the material 

 universe." And if, as is already abundantly 

 proved, matter itself is but a transition stage in 

 the evolution of something else, we can plainly no 

 longer speak of its conservation. 



Premising, then, that physicists are now coming 

 to believe that radio-activity is a property of all 

 40 



