( 137 ) 



Having determined the value of E, we find the law of attraction 

 by changing the sign and differentiating with respect tor. Of course 



nr 



\ve must first replace c by . The value which we find for the 



or* t 



force is negative; this indicates that the force represents an attraction, 



as we knew beforehand that we should find. The lowest degree of 



1/r which occurs in the series is the seventh degree, therefore the 



force will vary more rapidly than proportional to — . 



r 1 



. In connection with this result I wish to make the following remarks. 

 1 st The law for the attraction which we should find on the sup- 

 position of vibrating double points whose distance is small compared 

 with the wave length, will probably not differ very much from the 

 law established here, though this question cannot as yet be answered 

 with certainty. 



2 nd If we assume that m, without being periodical can yet increase 

 or decrease under the influence of <£, then we find a still more rapid 

 variation with r. 



Also if we assume that the molecules are not simple double points 



but more complex configurations, quadruple or octuple points for 



instance, we find a more rapid variation with r. The double points 



assumed here seem to yield the slowest variation with r that we can find 



when we interpret the molecular forces by means of equal positive and 



negative electrical charges in the molecules. Much sooner, therefore, 



than to assert that the electron-theory supports the supposition of a 



1 

 molecular attraction proportional to — we are justified in declaring 



that this supposition is excluded by the electron-theory. 



3 rd . If we assume m to be independent of the temperature T, 

 then the attraction which we find, does, indeed, depend upon the 

 temperature and that in such a way that at increasing temperature 



1 

 it decreases more rapidly than — . We have, however, no reason 



for supposing m to be independent of T , moreover it makes here 

 an enormous difference whether we are dealing with constant or 

 with vibrating double points. It is therefore impossible to say whether 

 the electric explanation of the molecular forces justifies us in assuming 

 the attraction to increase or to decrease with T. 



4 th . We may wish to determine the shape of the equation 

 of state which follows from the here assumed suppositions as to the 

 action of the molecular forces. If we then follow the virial-method 



