464 



wliicli the varialions of pre.ssiii-e of noble <>ases wei-e subjected to 

 a closer examination and tiie dependence of the effects found 

 on different variables was given in an approxinnalive "empirical" 

 formula. 



^ 2. Purpose. 



After having thus established our priority, we set ourselves the 

 task : 



1^*^ . to show that the experimental results obtained by A. Rut- 

 TENAUER in his extension of the investigations on the pressure effect 

 correspond to the theoretical formulae developed bj us in I, in 

 which also the practical part of Ruttenauek's empirical formula is 

 included ; 



2'"l to piove that serious objections may be laised against Skaupy's 

 theoretical view of the pressure effect; 



3'^. to draw further conclusions from Rüttenauer's important 

 determinations, also in connection with our earlier data on this 

 subject, and our objective, quantitative determinations on light 

 emission in continuous current discharges in spectrum tubes likewise 

 published in our Thesis. 



§ 3. Formula for the calculation of the pressure-effect. 

 RtJTTENAUEK gives the empirical formula: 



Ag \/M I 



Lp—f — .— 



p Q 



in which A/; represents the difference of pressure found, ƒ a constant, 



A the current density, g the gradient of tension, M the molecular 



weight, p the total gas pressure, / the length of the pos. pile, Q 



its cross section. 



It is seen from this that Rüttenauer tinds experimentally that the 

 pressure effect would be in inverse ratio to the total gas pressure ^), 

 whereas the author of this paper found — also experimentally — 

 that with not too great variations of p, hp varied little, if at all, 

 with p. *) 



How is this difference in result to be accounted for ? 



^) Which was, indeed, also mentioned by F. Skaupy in his first publication 

 (1917). 



2) Rüttenauer is erroneously of opinion that it would have been found both by 

 me and by Skaupy that in argon the pressure efTect is in inverse ratio to the 

 gas pressure. It was on the contrary observed by us that within certain limits 

 the pressure etTect showed a very slight variability with regard to the gas pressure. 



