944 Mr. A. M. Mosharrafa on the Appearance of 



present paper a closer approximation is worke'd out, and it 

 is found [see § 4] that for stronger fields than those used by 

 Stark this symmetry no longer follows from the theory : on 

 the other hand, a pair of components which, for fields com- 

 parable with those that Stark used *, appear symmetrically 

 situated, would for stronger fields be displaced in the same 

 direction, so that the symmetry is destroyed. We, naturally, 

 also find that the relation between the strength of the field 

 and the displacements of the lines is no longer represented 

 graphically by straight lines, but by parabolic curves whose 

 curvatures change sign with the displacements (i. e. displace- 

 ments of opposite signs correspond to parabolas of opposite 

 curvatures). 



It appears to the present writer that an experimental 

 investigation of the Stark effect for fields stronger than 

 those that have already been employed by Stark is highly 

 desirable as a further test of the fundamental hypotheses of 

 the quantum theory of spectra : if such an investigation result 

 in the verification of the predictions already referred to, then 

 tltis will add to our faith in the foundations of the quantum 

 theory of spectral lines : whereas a negative experimental 

 result would, unless the analysis here presented be at fault, 

 lead us to a reconsideration of our assumptions, and perhaps 

 to certain modifications thereof. 



§ 2. Previous Work. 

 The equations restricting the motion of an electron moving 

 under the influence of an attraction towards a nucleus as well 

 as a fixed force F can be written in the form 



J £ = | V7i(? ) d^nji, J„ =J s/f 2 (v) dv = n 2 h, "j 

 WmA etdyjr = n 3 h, 



} 



where h is Planck's quantum of action, n x n 2 n z are whole 

 numbers, m is the mass of the electron, and /i(f ) /2O7) are 

 given by 



-f/i(£)=2(*E+y8) + 2WP-«F6«-g, ] 



m, 



±f 2 [ V ) = 2(e-E-j3) + 2W V * + eFn i -^ 



I ■ (2) 



* For the H lines, e. g., Stark used a field of about 28,500 voltx cm.-i 

 ( = 95 c.G.s. electrostatic units). We find that a field of about 10 times 

 this strength would give quite measurable effects. 



