On High Frequency Spectra. 403 



elusion that the radium-bearing layer either does not extend 

 for a great distance From the springs in the direction of the 

 wells, which were all on the same side of the springs, or 

 that the layer slopes down to a greater depth. Thus the 

 supply of emanation seems to come mainly from a relatively 

 limited area. 



If we make the assumption that the supply of emanation 

 is constant throughout the year, then the greater radioactivity 

 when the springs yield little water is to be attributed to a 

 greater concentration of the emanation in the water. When 

 the output of water is greater, then the same, or almost the 

 same, amount of emanation is absorbed by a greater quantity 

 of water, the solution becomes more dilute, and we get a 

 smaller radioactivity of the water. 



From Professor R. R. Ramsey's results and my own obser- 

 vations^ it follows that we cannot draw a conclusion a priori as 

 to the variation of the emanation-content of a given particular 

 spring with the change in the flow of water. The connexion 

 between the two quantities depends on local conditions. 

 Experiment alone can decide what that particular connexion 

 is in a given case. 



Summary. 



The radioactivity of the hot spring at Tuwa is less when 

 the spring yields much water than when the supply of water 

 is relatively small. 



This behaviour of the spring does not disprove Professor 

 R. R. Ramsey's results. It can be explained by local 

 conditions. 



Physical Laboratory, 



St. Xavier's College, Bombay. 

 1st January, 1916. 



XL VII. On the High Frequency Spectra of the Elements Gold- 

 Uranium. By Manne Siegbahn, Dr. phil., and Einar 

 Friman, Lie. phil* 



1. IN the X-ray spectra we have, as well known, a reliable 



J_ method of determining the ordinals of the elements, 



and hence a method of detecting missing elements. Thus, 



for instance, Moseleyf, in his excellent researches on the 



* Communicated by the Authors. 



t Phil. Mag. [6] vol. xxvii. p. 703 (1914). 



2 E2 



