6 THE THEORY OF IONS 



have their energy transformed into exhibitions of 

 force of a very high character, and that as the atoms 

 break up some of the matter with its accompanying 

 kinetic energy is thrown off in the form of electrons 

 or metabolons. 



It is the " internal energy stored up in the chemical 

 atom " which is set free during radio-activity, and 

 it is of far greater magnitude than that exhibited 

 during chemical changes. 



The conception of an atom as a system is contrary 

 to preconceived ideas of the nature of matter ; and 

 the idea that atoms may become disintegrated gives 

 a new view to our conception of matter. It has 

 hitherto been considered that an atom was the lowest 

 stage in the composition of an element ; but if the 

 knowledge gained from radio-activity proves to be 

 correct, we have exhibited to us the fact that the 

 elements themselves may disintegrate. Although 

 atoms are chemically the lowest stage of matter, yet 

 physically such atoms undergo changes, and such 

 changes indicate that there may be an evolution of 

 matter, that such evolution consists in the trans- 

 formation of elements of one atomic weight into 

 elements of a different atomic weight and exhibiting 

 different characteristics. The work of Crookes, 

 Wendt, Preyer and others, leads to the assumption 

 that the elements are not the simple homogeneous 

 and unchangeable materials we previously con- 

 sidered them to be ; but that they are compounds 

 of atoms whose systems consist of different numbers 

 and various groups ; that the seventy substances 

 known and believed to be elements may be arranged 

 into eight groups, and the arrangement of such 



