﻿13<^ Positive Thermions from the Salts of Alkaline Earths. 

 Magnesium Fluoride. 



V. 



402 



H. 



d. 



2., 



e/m. 



800 



(e/m) K+ 



2400 



1-23 



•285 



25S 



249 



Collected Results. - 



In fig. 4 the results of all these experiments are gathered 

 together and exhibited graphically. The scale at the bottom 



— > -*■ 



10 



30 



Fig. 



4. 



200 300 



., - 400. 













Ba' 



5r. K. 



' Na. 



Ca 



•>• + 









1 



i a 



i 



A 







3a. 



5r. 





Ca. 



Mg. 





+ 





! 



» 





s 



1 







BARIUM 





Hill II II III 1 







1 1 









5TR0HT1UM 







III 1 ID 1 



1 











CALCIUM 











III III 1 Ml 



1 







MAGNESIUM 











1 1 MM 



III III 1 





— 2X — 



1 



2. 





$ 



4 









of the figure represents values of 2x, while that at the top 

 gives the corresponding values of e/m subject to the conditions 

 that V = 350 volts, that H = 2900 gausses, and that d = 1'3 cm., 

 which are taken to be approximately the mean values of 

 these quantifies. In the space labelled " -j- + " the heavy 

 vertical marks designated " Ba," " Sr," &c. are placed 

 beneath the values of e/m for these elements as calculated 

 from chemical data. The corresponding readings on the 

 lower scale therefore indicate the distances by which the 

 peaks of the experimental curves would be separated pro- 

 vided the emission were that of the ions in electrolysis, and 

 provided V, H, and d had the values already mentioned. 

 In the next space the values of 2a: in like manner correspond 

 to atoms of " Ba," " Siy" &c, carrying single charges. In 

 the space labelled " Barium " the vertical marks correspond 

 to the experimental values of e/m from all the salts of barium 

 examined. The results for the other salts are exhibited in 

 the remaining spaces. The length of the heavy black mark 

 in the lower left-hand corner of the figure represents the 

 width of the slit on the scale of 2x. 



Exhibited in this manner the results of these experiments 

 point strongly to the conclusion that the truly characteristic 

 positive thermions from salts of alkaline earths are single 

 atoms of these elements minus single electronic charges. 



