36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



the gaseous state, because they are so much weaker than the primary 

 forces ; although this may not be so invariably, just as it is not true 

 that the primary forces are always effective in holding together the 

 parts of the molecule of a gas (cf. N 2 4 , or I 2 ). But the residual 

 forces within a molecule might affect its properties considerably. 

 These forces, as they are magnetic, will be forces of attraction 

 wherever possible, and we can in many cases form a rough idea of 

 their distribution, magnitude, and influence on the molecule. 



Let us first consider the factors that would 



a a determine the amount of attraction between two 



Nlys mv$ magnetons. In the case of simple groups, such 



* " as groups of two each, it is evident that they 



/J cliw must take up certain " complementary " attitudes 



It |J towards one another, as shown in the figure, if 



there is to be any great amount of attraction 



between them, and such complementary attitudes are not possible 



unless the two groups are very similar in structure. For instance, 



4* *$ 



AND 



the two groups /\(\I0 ^"k can attract eacn other 



when in the relative attitudes I have depicted, but not so much as the 

 more symmetrical pair first mentioned. 



This principle seems to be perfectly general ; and, in applying it 

 to the present theory, we can distinguish between two very distinct 

 types of groups : ( i ) groups of eight, with their stable symmetrical 

 distribution of magnetons; and (2) less symmetrical groupings, 

 where the magnetons are " free " or in positive bonds (no doubt 

 further distinctions could be made here). 



The group of eight has a symmetrical but very checquered field, 

 and is not fitted to attract a single magneton very strongly, or any 

 group that is not very similar to itself. In the same way, less regu- 

 lar groups may under favorable circumstances have more attraction 

 for one another than they could have for groups of eight. 



Not the least important feature of these attractions is that the 

 external field of a group of any kind of structure will tend to impose 

 a similar structure upon any neighboring group, so as to increase 

 the attraction between them and lower their mutual energy. This 

 tendency will affect irregular groups more than groups of eight, for 

 their magnetons are less firmly held, so that irregular groups will 



