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BELL SYSTEM TECHNICAL JOURNAL 



carbon, with boron and with iron in place of the aluminium, and each 

 had a peak at the proper situation for protons. 



It seems, then, that the particles are protons. They are of the same 

 kind, whatever the substance they come from; though the speed which 



I / ! 



1/ 



/I 



I 



Fig. 3 — Part of Stetter's apparatus for studying transmutation. 



they have when expelled, and the plentifulness of the expulsions, varies 

 notably from element to element. This suggests that they are con- 

 stituents common to all elements, though the manner in which they 

 are bound into the atomic structure differs from one to another. 

 According to our knowledge of the astronomy of the atom, the nucleus 

 is the only part where they can be. Moreover, though the masses of 

 nuclei generally are not exactly integer multiples of the mass of the 



