56 PRESIDENTIAL ADDRESS SECTION B. 



to the two hydrogen nuclei. Rutherford gives the following 

 diagram : — 



3++ 3++ 



e B.+e h+0 



3++ 3++ 

 for the nitrogen nucleus, but expressly states that the arrangement 

 is arbitrary. Since carbon and oxygen give no hydrogen particles, 

 Rutherford infers that carbon nucleus is 



3 + + 3++ and oxygen nucleus is 3 + + 3++ 

 6 6 He++ 6 



5 + + 3++ 3++ 3+ + 



the three elements N, C, and O thus being depicted as having in 

 their nuclei an excess of plus charges which is 7, 6, and 8 respec- 

 tively, agreeing with their atomic numbers. As explained above, 

 the 3 + + and He++ particles are not capable of being disintegrated. 



To complete this series it may be mentioned that boron nucleus 

 appears undoubtedly to be nitrogen minus 3++, viz., 3++ 3 + + 



8 H+ H+ 6 

 3++ 

 (See Fig. 10.) 



I am immensely interested in these conclusions, for some of 

 you may remember that many years ago, long before the concep- 

 tion of a nucleus for the atoms arose, I predicted* that nitrogen 

 would be found to be CX in which X is an unknown element of 

 atomic weight 2. This prediction was made on purely chemical 

 grounds such as the relation of pyridine to benzene. 



I also predicted that carbon would be found to consist of a 

 tetrahedral arrangement of 4 sub-atoms of weight 3, and that 

 oxygen is CX 2 . This paper gave rise to an active discussion, 

 hingeing mainly on the isomerisms which would be postulated by 

 such a theory. Thus nitrogen gas and CO gas would be isomeric 

 both being C 2 X 2 . The extraordinary physical resemblance of these 

 two gases has been recently dealt with by Langmuir. 



On Rutherford's modification of my theory the two gases are 

 no longer isomeric but metameric, because the nuclei differ in 

 weight, but in all other particulars of their constitution they are 

 essentially the same, as will be seen later on. 



There appears to be some chance that the element of atomic 

 weight 3 from nitrogen, which I ventured to call zoicon, will be 

 found in minerals. After it has lost its positive charges by hitting 

 electrons the 3++ particle must become an inert gas closely 

 resembling helium and possessing a spectrum similar to that of 

 helium with a displacement. This is on the assumption that the 

 inert gas will have two external electrons just as helium gas has. 

 If, however, it has one electron inside and another outside, this 

 deduction would not hold and it would become possible that the 

 new gas is the nebulium of the nebulae, with the constitution 

 (03++)d and a spectrum more like that of hydrogen than that 

 of helium. The 3 + + particle is itself probably complex, viz., 



* " Some suggestions for a new atomic theory," Jotirn. Chem . Mefall. <$■ Mining Soc, S.A. 

 April, 1909, page 335, also September, 1909, page 98. 



