Connexion betiveen j3 and 7 Ray Spectra. 315 



probably a close double which it is difficult to separate under 

 the experimental conditions. One component is believed to 

 belong to radium B and the other to radium C. This appears 

 very probable, for Hichardson has found recently that 

 radium C emits some 7 radiation which has about the same 

 absorption in lead as the soft 7 rays from radium B. We 

 should consequently anticipate that radium C should give a 

 strong line near 1° 40' of energy about *75 x 10 13 e — in good 

 agreement with the unit found above. 



Only two strong lines remain which are not included as 

 multiples of these two units *74 and 1*29 x 10 13 e. These are 

 the two lines A and B of energies 2T02 and 17*5 x 10 13 <?. 

 These can be expressed as 12 E and 10E whereE = 1*75 x 10 13 £. 

 In appears more than a coincidence that this value is very 

 close to the energy of the shortest wave-length observed for 

 the 7 rays from radium C, viz. 43' of energy 1*74 X 10 13 £. 

 It was also found that several lines in the spectrum were 

 multiples of the energy of the strong /3-ray line of energy 

 1'81 xl0 13 £. This corresponds to nearly twice the energy 

 of the line 1° 24' of energy '89 x 10 13 e. 



There are a number of other faint lines not included in 

 the above tables. It is probable these may owe their origin 

 to other frequencies not observed in the 7-ray experiments. 



It is seen from the above that there is strong evidence 

 that the energies of many of the lines in the /3-ray spectrum 

 may be expressed as integral values of certain definite units 

 which correspond with the frequencies of vibration of the 

 7 rays, assuming Planck's relation between frequency and 

 energy. It hardly seems possible that the numerous close 

 agreements observed are accidental ; for it must be remem- 

 bered that the units are chosen to fit in with three strong 

 lines of comparatively slow velocity observed in the /3-ray 

 spectrum of radium C, whose energies are 1*81, 2*59, 

 2*96 x 10 13 e, where the multiple is 2 for the first two units 

 and 4 for the last. 



If these deductions are correct, it follows that not a single 

 7 ray but a train of 7 rays of definite frequency can be 

 emitted from each vibrating centre of the atom. The number 

 of waves composing the train varies for different atoms and 

 for the different frequencies, but evidence is obtained that 

 the number of complete waves may in some cases be ten or 

 more. The train of waves on passing through matter may 

 under suitable conditions give a n ft g energy to a single 

 electron, and thus give rise to the high speed electrons 

 when 7 rays pass through matter. A Ye have already drawn 

 attention to the fact that the primary ft rays emitted from a 



