On the mass of the proton

1. This paper develops, and to some extent amends, the theory of the relation of the proton to the electron suggested in a “Preliminary Note on the Masses of the Electron, the Proton, and the Universe.” As explained in that note, my discussion of the constant 137 opened out into a wider investigation embracing other natural constants, and it seemed necessary to pursue this before attempting to perfect the theory of 137. The first result of this extension is contained in a paper on “The Value of the Cosmical Constant.” This is primarily a theory of the mass of an electron; it is satisfactorily confirmed by the observed velocities of recession of the spiral nebulæ, and I think it must be substantially true. But the acceptance of this theory of the electron has the consequence that the relation between the electron and the proton cannot come about quite in the way I had previously had in mind. Indeed, my first impression was that it closed the door to any symmetrical kind of relation between the electron and proton. For my own part, I think it most unlikely that there is any fundamental difference in the intrinsic nature of protons and electrons, and I should regard it as a serious objection to the theory of the cosmical constant if it insisted on such a difference. It is therefore important to show that there is an opening by which the proton is easily brought into the same scheme.