326 THE ROYAL SOCIETY OF CANADA 



The values given in Column IV, Table V, are recorded in Fig. 3, 

 those obtained from Millikan's work being indicated by crosses, 

 those by Horton and Davies by squares and that found by Holweck 

 by a triangle. The values given in Table IV are indicated by circles. 

 The graph denoted by No. 7 is taken to correspond to M X-ray 

 series of the elements tabulated. 



Curves Nos. 4 and 5, extensions of the line No. 6, it will be seen 

 pass through and fit in fairly well with values oi y/ V given in Tables 

 IV and V for the elements from Chlorine to Neon. From Neon to 

 Lithium the values of V F" lie approximately on a line designated 

 in the diagram as Curve No. 3. 



If we accept the values of the critical voltages given in Tables IV 

 and V, as the correct ones for the quantum equivalents of the first 

 numbers of the L series for the corresponding elements, the graphs 

 shown in Fig. 3 would indicate that the Moseley L series Law applies 

 very closely for all elements from Uranium to Neon. For the elements 

 lighter than Neon the square roots of the critical voltages lie on a 

 line, which is slightly concave, towards the atomic number axis but 

 which meets the line representing Moseley 's Law at the element Neon. 



If we conclude that the graph Nos. 3, 4, 5, and 6 correctly 

 represents the square roots of the quantum voltages for the La wave- 

 lengths of the elements cited, strong support is given to the view 

 that in all atoms heavier than Fluorine, the second shell or ring 

 consists of eight electrons and that the L series wave-lengths for all 

 elements including the lighter ones, originate in disturbances given 

 to the electrons in the group comprising the second ring or shell. 



In the endeavour to interpret the numerous and varied critical 

 potentials that have been found experimentally by a number of 

 investigators, including the authors, tv/o views have been presented. 

 According to one, the Moseley L series law is applicable for all elements 

 from Uranium to Argon. According to the other, the Moseley law 

 is applicable for all elements from Uranium to Neon. If we accept 

 the second view the critical potentials found by the writers and by 

 Richardson and Bazzoni, Hughes, Kurth, and Mohler and Foote are 

 left unexplained. On the other hand, if we accept the first view, the 

 correctness of Millikan's interpretation of his photographically 

 recorded spectra of the light elements is called in question. It is 

 clear that while very distinct and interesting advances have been 

 made in this field of research, further work will have to be done in 

 order to remove a few anomalies that still exist in connection with 

 determinations of the L series wave-lengths of the light elements. 



