338 PROCEEDINGS OF THE OHIO ACADEMY OF SCIENCE. 



another substance called radium A. and so on for a series of 

 transformations. 



Thus was shown for the first time that a transmutation of 

 the elements was possible. Radium is apparenth' one element in 

 a long series, which gradually disintegrating through their own 

 atomic instability, pass by degrees one into another. The dis- 

 integration, which during its action gives rise to radio-activity, 

 consists in general of the emission of alpha-rays, that is, of 

 helium. The atomic weight of each sucessive product is gen- 

 erally smaller by 4, the atomic weight of helium, than that of, 

 its predecessor in the series. It has not been found ]:)Ossible by 

 any chemical process to arrest or hasten this disintegrative proc- 

 ess ; the energy invohed is in fact vastly greater, perhaps on the 

 average a million times greater, than the energy connected with 

 the ordinary chemical transformations. It is not to be wondered 

 at that the alchemists were unsuccessful in their attem]jts at the 

 transmutation of metals. 



The element helium plays a remarkable role in all this. 

 Known since 1868, and given its name, only from its brilliant 

 spectrum as observed in the sun and stars, it was discovered, 

 but not recognized, in 1891, in the analysis of some uranium 

 ores for the United States Geological Survey, and some years 

 later was identified by Lockyer through its spectrum. Its atom 

 is now found not merely to be a definite element, but to form 

 a part of many other so-called elementary substances, which on 

 losing it. have thereby all their properties changed, and are 

 transformed into something else. 



This gradual disintegration of certain elements suggests the 

 larger question whether all the elements are likewise in process 

 of decay or transformation. It is not im])robable. It has been 

 calculated that in about fifty thousand years practically all the 

 radium now in the earth will have ceased to exist as radium. 

 Of course this does not imply that there will be no radium then, 

 for it is in all prol)ability continually produced by the disintegra- 

 tion of some other substance. Since radium occurs always in 

 connection with uranium, it has seemed i)rol)able that uranium 

 is in this sense an ancestor of radium, and within three months 



