NO. II STRUCTURE OF THE ATOM — PARSON 65 



of the behavior of the group. But when we remember that the earth's 

 field is for that model relatively very much stronger than any possible 

 field can be for actual atoms, it is easy to see that the paramagnetic 

 effect would be slight. 



The presence of free magnetons, on the other hand, would make 

 for paramagnetism ; but would not necessarily succeed in producing 

 it in all cases, for even " free " magnetons may form fairly stable 



X S 



groupings of no intrinsic moment, such as — ^ — — ^— for two, 



sN 



S , — ^ — for three, and so on. It must always be borne in mind 

 m/ N 



ys 



that the observed magnetic effect is the difference between the 

 separate paramagnetic and diamagnetic effects, as Langevin points 

 out; and unless it is large in proportion to the number of magnetons 

 in the atom, it gives very little clue to the absolute value of either of 

 them. (This explains those cases where diamagnetism seems to be 

 dependent upon temperature.) These considerations will make it 

 clear that, while any obvious contradictions will be evidence against 

 the theory, not too much in the way of positive correlation of mag- 

 neton constitutions with magnetic phenomena must be expected from 

 it at this first attempt. 



There follows now a set of references to the investigations from 

 which I have collected data, with the letters (in parentheses) by 

 which they will be referred to in what follows : 



(Q) Quincke: Gases at pressures up to 40 atm. : method of the effect of a 

 magnetic field on gas-liquid surfaces (Wied. Ann., 34, 401, 1888) . 



(C) P. Curie: Effect of temperature on the magnetic properties of typical 

 substances (Ann. de Chim. et de Phys., 1895). 



(M) Stephan Meyer: Magnetic properties of the elements, and periodicity 

 in them (Wied. Ann., 68, 325, 1899). A survey of all classes of inorganic com- 

 pounds in search of additive relations (Wied. Ann., 69, 236, 1899; Ann. der 

 Phys., [3] 1, 189, 1900). 



(L) Liebknecht and Wills: Cr, Mn, Fe, Co, Ni, Cu, in their salts (Ann. der 

 Phys., [3] 1, 177, 1900) ; du Bois and Liebknecht: Rare-earth elements in 

 their chlorides (Ann. der Phys., [3] 1, 189, 1900). 



(T) P. Tanzler: Susceptibilities of He, A, air, compressed in glass bulbs: 

 method of moment in a non-uniform field (Ann. der Phys., [5] 24, 931, 1907). 



(U) Urbain and Jantzsch: Rare-earth oxides (C. R., 147, 1286, 1908). 



(P) P. Pascal: The susceptibilities of many non-metallic elements and 

 easily liquefiable gases — all diamagnetic : also carbon compounds studied, and 

 additive relations found, but constitutive influences are very marked — all 

 diamagnetic (Ann. de Chim. et de Phys., 19, 5, 1908). The magnetism of V, 

 Cr, Mn, Fe, in relation to their state of combination (C. R., 147, 742, 1908). 



