PRESIDENTIAL ADDRESS SECTION B. 57 



H+ H+, (see Fig. 8), and the a- particle (helium nucleus) 

 ft 4++, isH+ H^ 



H+ 6 6 



(See Fig. 6.) H+ H+ 



As regards the monovalent element X = 2 which I predicted in 

 1909, Rutherford's discovery seems to indicate that it only exists 

 in nuclei and that it is constituted H+ 6 H+, so that it yields H 4 " 

 on impact.* This means that the a-particle is composed of two of 

 these X elements, and the 3 + + particle is composed of one X and 

 one hydrion.f The stability possessed by 3++ and 4++ is in my 

 opinion due to the symmetrical (viz., triangular and tetrahedral) 

 arrangement developed in them when they are made up from 

 H+ + X and X + X. In this way Rutherford's conception of 

 oxygen nucleus as CHe becomes the same as my conception of it 

 as CX 3 . 



In connection with this subatom X+, I am very pleased also to find 

 that Prof. Harkins, another pioneer of atomic structure, has now 

 come to the conclusion that it is "the primary group in atom 

 buildingj, and agrees with me that the as-particle is X 2 +. Harkins 

 by the way writes X+ as p 2 e, but his j> is the same as my notation 

 H+ and his e is the electron, so that p 2 e becomes (H+ 0H+), which 

 is my conception of X+. (See Fig. 9.) It is unfortunate that different 

 scientific writers should use different terms for the same entity, and I 

 suggest that H+ should always be called hydrion, not hydrogen- 

 nucleus or proton or H-particle. X+ should also have a name, since 

 "isotopic hydrogen" is unsatisfactory; possibly the name aerion 

 would do. Harkins uses the very suitable name neutron for the 

 nuclear combination (H+ 6), which is required according to Ruther- 

 ford and himself to account for the existence of the elements whose 

 atomic weight is greater than twice their atomic number (see 

 rubidium, p. 51). Thus chlorine nucleus of at. wt. 35 is X 17 + .V, 

 in which N stands for one neutron, and 17 is the atomic number. 

 Aston's chlorine-nucleus of at. wt. 37 is then X 17 +iV T 3 . 



Assuming then the sub-atom X+ ( — H+0H+), an extra- 

 ordinary connection between the nuclei of inert gases and the satur- 

 ated hydrocarbons can be demonstrated. CX 4 adds up to 20 and 

 corresponds to neon. C 2 X 6 adds up to 36 and corresponds to the 

 lower isotope of argon, with the constitution CX 3 CX 3 . Again 

 C(CX 3 ) 4 = C 5 X 12 (cf. tertiary butane) adds up to 84 and agrees 

 with the nucleus of krypton and has also the required round shape. 

 Similarly C 8 X 18 adds to 132 which agrees with xenon, and C 14 X 3n 

 adds to 228 which may be the highest isotope of niton. Adding 

 three a-particles to this niton gives U = 240. The highest possible 

 element would then be C 17 X 30 = 276 = C [C(CX 3 ) 3 ] 4 . Some 



extra binding-electrons are required to give the correct atomic 

 numbers. This kind of formulation puts all the X's to the outside 

 of the nucleus, and thus explains radioactivity, as the X's get 



* He says (Bakerian Lecture) " It seems very likely that the electron can also bind two 



nuclei this entails the possible existence of an atom of mass 2 carrying one 



charge, an isotope of hydrogen," i.e. monovalent. 



t I predicted this also in 1909. 



X Nature 1921, p. 203. 



