Experiments on Polarized Rontgen Madiation. 795 



in the coil was placed at XX, directly opposite the slit S 4 in 

 the lead screen, and its diameter was slightly greater than 

 that of the slit. 



In the first part o£ the experiment the iron was un- 

 magnetized, and the ratio of the intensities of the tertiary 

 radiations reaching the electroscopes A 1 and A 2 from R 2 was 

 determined. This involved two measurements : — (1) the 

 intensities when the radiator E 2 is present ; (2) the intensities 

 when the radiator R 2 is absent. By subtracting these two 

 readings the required ratio was determined. The iron was 

 then magnetized, and this ratio again measured. It should 

 be stated that the deflexion in the electroscopes when the 

 radiator E 2 is absent is due largely to natural ionization 

 and the electrostatic leak across the ebonite which supported 

 the gold leaf, only a negligible fraction being due to that 

 scattered from the slit at S 5 and from the air. This was 

 shown by removing E 2 and measuring the leak in the two 

 electroscopes, firstly when Rj was present, and secondly when 

 "R-j was absent. There was next to no difference in the two 

 deflexions, showing that the scattering effect is negligible 

 when R 2 is absent. 



In the Tables I. and II. a complete set of observations 

 is given, and in Table III. the final results obtained in a 

 similar manner are summarized. The time of observation 

 varied from ten to fifteen minutes. 



Table I. 

 Iron in a magnetic field. — Intensity of field =320 gauss. 



Conditions of experiment. 



Deflexion of 

 electroscope 

 receiving hori- 

 zontal tertiary 

 beam. 



Deflexion of 



electroscope 



receiving 



vertical tertiary 



beam . 



Carbon radiators B x + E., present. "1 



Carbon radiators E, 4-E 2 present. 1 

 Iron magnetized j 



14-4 

 144 



8-3 



6-3 

 64 



4-8 



Carbon radiator E x present, E ] 

 absent > 







Carbon radiator E T present. 



At E, an arsenic plate J 



7-8 

 62 



4-4 

 2-8 



Carbon radiator E T present. "1 







