Chase.] - ^50 [April 21 



I have added Tl and Rb to the elements which Gerber included in his 

 monatomic group. J,, J^ J^, are the ratios of the differences between 

 H, y and D^, respectively, and the values which may be found by a divis- 

 ion of Clarke's atomicities by the theoretical atomicities. The arithmetical 

 mean values correspond with the order of arrangement, viz. : J^, .0028 ; 

 J2, .0034 ; J3, .0036. 



Di- or Tetratomic / a = Dj. 



These are the same elements as are embraced in Gerber's second group. 

 The arithmetical mean values of the deviations are, Ji, .0025 ; Jo, J3, 

 .0033. 



