Manchester Memoirs^ Vol. xlviii. (1904), No. 8. 41 



able area is taxed for the supply. At first sight it seems 

 that the atomic theory, which bears out and is borne out 

 so strikingly by atomic disintegration, opposes a barrier 

 to any conception of atomic up- building. A gradual 

 and continuous accretion of atomic mass in which the 

 energy was supplied in very small steps as available from 

 the low-grade heat energy of the surroundings seems the 

 only process readily conceivable. But the atomic theory 

 appears to demand equally with ?i per saltum degradation, 

 a per saltum accretion. This difficulty is however not 

 real. We have only to account for the step-by-step 

 increase in the complexity of atoms as known to us. It is 

 not necessary to assume that it is impossible for inter- 

 mediate forms (representing a practically continuous 

 increase of atomic mass from the lightest to the heaviest 

 known atom) to be altogether incapable of existence. All 

 that is required is that the rate of accretion of mass should 

 be more rapid between the points of stability as repre- 

 sented by the atoms of the periodic table. This would 

 ensure that the intermediate-forms in the up-building 

 process, like the transition-forms in that of disintegration, 

 would never accumulate in sufficient quantity to have 

 been yet detected by direct methods. These views belong 

 at present to the realm of pure conjecture, but it is an 

 era of speculation with regard to the constitution of 

 matter, and the more the problem is regarded from inde- 

 pendent points of view the more likely is the speculation 

 to prove fruitful. The old order changeth, giving place to 

 new. Electrons are regarded as constituents of atoms, 

 and from that view to the ideas advocated by Sir William 

 Crookes that atoms are composed entirely of the same 

 constituent or protyle is at least a possible step. Is an 

 electronic accretion of atomic mass as indicated above 

 within the regions of possibility ? 



