﻿Variation of Triple-Point with Hydrostatic Pressure. 143 



An examination of the results in Table II. shows that 

 though the values obtained for N by the formula of Curtis 

 are slightly more consistent among themselves than those 

 obtained on the hypothesis of magnetic action, the diver- 

 gence in the latter case is not too large to make this 

 hypothesis untenable. The results with 5 magnetons are 

 slightly better than those with 6 magnetons. 



In support of the view that the core contains 5 magnetons 

 we have the fact, first pointed out by Chalmers, that the 

 magnetic moment produced by an electron moving in a 

 circular orbit with angular momentum Ji/2tt is exactly 



5 magnetons. 



The value of the series constant N would then be 

 109, 679*26, and the convergence frequencv of the series 

 would be 27419-815. These values differ 'but little from 

 those given by Curtis, and consequently the wave-lengths 

 of the remaining lines of the series would be practically 

 identical with those given in Table V. of his paper. 



On the other hand, the hypothesis that the core contains 



6 magnetons appears to receive support from the observed 

 diamagnetic properties of hydrogen, and it may be pointed 

 out that the magnetic moment of the core in this type of 

 state would then be 3 times (corresponding to m = 3) the 

 moment of a sphere rotating with the angular velocity 

 specified in earlier papers. This would give 109,679'25 as 

 the series constant, and 27419*813 as the convergence 

 frequency. 



Thus it appears that it is possible to account for the 

 series spectrum of hydrogen on the lines of Bohr's theory 

 combined with the assumption that the core of the atom 

 can produce a magnetic field equivalent to that set up by 

 either 5 or 6 magnetons. 



In conclusion, I desire to express my thanks to Pro- 

 fessors J. W. Nicholson and 0. W. Richardson for their 

 advice and suggestions. 



University of London, King's College. 



XIV. On the Variation of the Triple-Point of a Substance 

 with Hydrostatic Pressure. By Alfred W. Porter, 

 D.Sc., F.E.S.* 



P"|^HE fact, the truth of which is now well recognized, that 



A the saturation vapour-pressure of any liquid or solid 



is a function of the hydrostatic pressure, carries with ir 



sundry consequences. One of these is that the triple-point 



* Communicated by the Author. 



