#68 Dr. Kovarik and Mr. Wilson on the Reflexion of 



Subtracting (1) from (2) we obtain the ionization due to 

 multiple reflexion of! the /3-particles plus the initial ionization ; 

 subtracting (4) from (3) we obtain the initial ionization of 

 the incident j3 rays alone. The difference of these two values 

 divided by the latter gives a ratio which is taken as a measure 

 of the reflective power of the substance for the /3-particles of 

 the velocity under consideration. Owing to the fact that P 

 had to be always in position and that some reflexion must 

 occur in the ionization chamber even when Q is absent, this 

 ratio is of necessity somewhat low, yet, the conditions being 

 the same for rays of all velocities, the change of this ratio 

 indicates the changes in the reflexion of the /3-particles of 

 different velocities. 



Experiments were made with lead, copper, and carbon. 

 The /3-particles considered were those between the values 

 Hp = 1164 and Hp = 7b'()0 gauss cm. The results obtained 

 when the angle of inclination was 45° are in Table Land 

 plotted in the curves of rig. '2. 



Table I. — Ionization vessel inclined 45° to the horizontal. 





Ratio of the ionization due to 







multiple reflexion alone to the 







ionization of the incident rays. 





lip iii 





^ (from curves). 



gauss cm. 











Pb. 



Cu. 



C. 



1164 



0-56 



0-25 



002 



2-56 



1372 



094 







2-38 



1700 





0-53 



o : ib 



225 



2072 



1-36 





0-23 



2-08 



2480 



T57 



0-78 



0-26 



1-91 



2920 



1-60 



0-77 



027 



2-04 



3400 



1-64 







2-04 



3900 



1-64 



: 77 



026 



2-08 



4340 



160 







2-05 



4720 



1-58 



0-77 



025 



210 



5000 



156 





022 



212 



5380 



T53 



0-71 





212 



5720 







o : i*8 





6040 



1 : 46 



: 64 





2 V 12 



6320 



1-42 







2-22 



6600 



1-33 



: 67 



o : ie> 



2-18 



6850 



1-31 





... 



2-11 



7080 



1-31 







229 



7280 



1-15 



: 64 



0-21 



2-30 



7480 



1-20 







2-34 



7660 



1-08 







2-36 



2*18 mean 



