on the intensity of spectrum lines 433 



from the line spectra obtained with a condensed spark. The dense 

 line at 4277-7 a.u. brought out very strongly by the field is generally 

 absent without it, especially when the gas is not quite pure. With 

 a condensed discharge it is rather faint. It has been catalogued as 

 a negative pole band by Exner and Haschek*. 



The phenomena attending the employment of the magnetic 

 field are many and varied and complications arising from local 

 variations of potential current, temperature and pressure known 

 to occur there are difficult to eliminate entirely. But by inde- 

 pendent variations of some of these factors it has not been possible 

 to reproduce the phenomenon observed and hence the phenomena 

 cannot be attributed entirely to these disturbing causes. It is 

 possible that it might be due to some other influence brought 

 about by the field. Further study of the phenomenon is in pro- 

 gress. 



In conclusion I beg to express my indebtedness to the kind 

 and sympathetic help of Professor Sir Ernest Rutherford through- 

 out this work. 



Cavendish Laboratoky, 

 Cambridge. 



* Kayser, Handbuch der Spectroscopie, vol. 5, p. 826. 



28—2 



