CHANGES IN SCIENTIFIC OPION 15 



these was a simple and undecomposable sub- 

 stance incapable of being split up or of being 

 transmuted into anything else but itself. And 

 so the underlying theory became and for long 

 remained one which proclaimed an essential 

 and absolute difference between the so-called 

 chemical elements. 



Time rolled on, and but a few years ago Radium 

 M. and Mme. Curie discovered radium, and the 

 extraordinary facts of radio-activity began to 

 be gradually brought to light. Following upon 

 these discoveries has arisen a new theory of 

 matter wholly different from that which has for 

 so many years held the field. This theory 

 teaches that within the atoms of which all 

 chemical elements are made up are electrons 

 or corpuscles, and that these corpuscles may 

 be moving units of negative electricity, en- 

 sphered by an envelope of positive electricity.* 

 Moreover, it teaches that the differences be- 

 tween the atoms of any two substances is a 

 difference of arrangement in the ether with 

 which they are associated. Now a single glance 

 will show that this is really very close to the 

 theory of the alchemists, as will be more fully 

 shown in a succeeding chapter. If all things 

 in their ultimate analysis are constructed from 



* There are other views, for which manuals on Physics 

 and on the Composition of Matter must be consulted. 



