[eve] CURRENT IN A CARBON FILAMENT LAMP 179 



(Rontgen Rays and Crystal Reflection.) 



The German Scientific Journals are not at present reaching Can- 

 ada. It may therefore be of interest to place on record that in a 

 recent number of the "Physikalische Zeitzchrift" there is a note 

 by Seeman of Wurtsburg together with a beautiful photograph of 

 the X ray spectrum of platinum. "It is absolutely filled with fine 

 lines from 2° to 12° including the strong lines found by Bragg and 

 Moseley. He has used a remarkably perfect crystal of rock salt 

 and a very penetrating X ray bulb" (Rutherford). This note has 

 come to me by way of Copenhagen and Manchester. It is clear 

 that it will be possible to determine the exact values of the extremely 

 short wave lengths of the various X rays stimulated by cathode rays 

 in the electronic systems within platinum atoms. It is remarkable 

 that the lines should be fine, indicating precise oscillation periods. 

 The measurements when made will probably throw further light on 

 the interesting quantum theory. 



A. S. Eve. 



