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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



The exceptional cases 



a 



a ^ 5 @=NS 



N— 



can reasonably be attributed to the fact that in the case of penta- and 

 hepta-valent elements those oxides which have an even number of 

 free magnetons in the atom are bound to have cumbrous molecules 



like (^^-(O^N^^O). 1 



The frequent occurrence of a pair of magnetons as a subsidiary- 

 group in the outer part of the atom, and its comparative stability, are 

 the reasons for the use here of the symbol a to represent it. 



Unsaturation in Carbon compounds is quite a different kind of 

 phenomenon and will not be discussed in the present paper. 



§13. The Transition Series of Elements 



In §6 constitutions were assigned to the elements of the series as 

 follows : 



They were based on an arbitrary assumption — that in certain specified 

 cases (i. e., in the middle of the long periods) the group of eight was 

 not formed by eight or more free magnetons. The justification for 

 this is that it enables us, without any further assumptions whatever, 

 to systematize and explain the outstanding properties — at first sight 

 so irregular — of these elements. 



In the first place, some of the properties of the first four are quite 

 normal. For example, Mn, which is 3y + 7, although without nega- 

 tive action, has a positive valence of seven, as is shown in Mn 2 7 

 (cf. C1 2 7 ) and KMn0 4 (which is isomorphous with KC10 4 ). 

 Similarly, in the nature of their higher oxygen derivatives, V and Cr 



1 The kinetic effect here implied should of course be taken into account con- 

 tinually in any complete analysis of the behavior of atoms, but it is difficult to 

 see how this can be done even in a qualitative way except in the very simplest 



