Atomic Volumes and the Spectra of Elements. 



023 



v = 



P 



\l Ll 



me S* La 2 (a -t- ?i)' 2 J ' 

 an expression almost identical with 



»= 1,2,3, 



- N °C~(/> + >0 2 ) 



being Rydberg's formula to represent a series of lines in 

 spectra ; a and b are constant for each element, N is con- 

 stant for all elements. Both formulae approach a limit for 



w = x>, and we should expect % equal for all elements. 



S" 



The limit approached by Ritz's equation is 



e a 1 

 mc s~ a- 

 which is the root of the spectrum series, a is the ratio of 

 the distance of the electron from the nearest magnetic pole 

 to the length of one of these elementary magnets. We 

 might expect this ratio, or consequently" the root of the 

 series v , to be some function of some atomic dimension. 

 This seems to be the case, for if we plot on two orthogonal 

 axes the logarithms of the roots of the series and of the 



Fin-. 1. 



atomic volumes, the points representing elements of the same 

 family lie very nearly in a straight line (fig. 1). In other 



