SOME CONTEMPORARY ADVANCFS IN PHYSICS- I'll 297 



limiting freqiii-nry >-„,;„ for that \.iliie of llic energy E of the hotii- 

 f)arcling elcrlrons, which corresponds to the point on the axis of 

 abscissae where the curve (extrapolated) intersects it. Ihe relation 

 between ««„„, and E is the simplest of all relations: 



E = constant • v,,,.!, = // 



or 



The const. ml h is the saiiU' for all the nictais on which liic cNiu'rinii'iit 

 has been performed- a few of the least fusible ones, for metals of a 

 low melting-point would be melted before E. could be lifted far enough 

 to give an adct)uatc range for determining the relation between it and 



H%ti09 of in(tn9it>49 oflin*3 



*t400kv to Utoat dt iiSkv, 



^>Ot gtmrtJ rtdiition lublracttd), tre 



j5> jJ* jSj 



Vilu*3-of h giv*n by th^e curwa, 



tttaokv, ff6X-l0"»rg ate. 



- »ia •. h'ssf/o" - • ; 



" I3t ■■ . h-e33-o" - - 



Mu/i 0/4// h dUtrminttJOns on rhodi/m, 

 wiih tha vt/ue o/t 13 SSi-to" trgaee 



Fig. 5 — The continuous X-ray spectrum for three v.ihics of the energy of the bom- 

 barding electrons, intensity being plotted versus a quantity varying uniformly 

 with frequency. Ignore the peaks. (D. L. Vsc\is,lcr,\J'liysical^Review.) Sec footnote 6 



