534 Miss Jadwiga Szmidt on Distribution of Energy in 



But it is quite different in the case of H 2 S, where this 

 value is as high as 1'23. It seems, therefore, that to produce 

 the same number of ions in air and in H 2 S different amounts 

 of energy of the same kind are required (in the ratio 1 : 0*8), 

 and that the ionization in this case depends not only on the 

 atoms present, but also on their molecular arrangement. The 

 same abnormal behaviour of H 2 S has been noted by Barkla 

 and Simons in experiments with X rays*. 



In order to test whether the ionization by hard rays is 

 proportional to absorption, the ionization produced by the 

 7 rays of a thin-walled emanation tube (emanation, radium A, 

 radium B, and radium C in equilibrium) was measured, and 

 the- softer rays then gradually cut out by aluminium. Two 

 curves were obtained with air and S0 2 in the ionization- 

 chamber. The effect for S0 2 without absorption sheets was 

 2*67 times larger than for air, but as sheets were added and 

 the soft rays from radium B cut out, this ratio dropped to a 

 constant value about 2*1. The relative ionization for hard 

 rays is therefore about 2*1; the relative absorption being most 

 likely 2'26, the total relative ionization in S0 2 in the case of 

 hard y rays is also not far from 1. This seems to show that 

 there is no essential difference in the process of ionization of 

 simple gases by hard or by soft y rays. 



Let A be the amount of ionization in air ; out of this 

 about 92 per cent, is due to the hard rays from radium B 

 and radium C. In S0 2 these rays give 2*1 times as much 

 ionization as in air; let x be the corresponding factor for 

 the soft rays. Then 



0-92Ax 2-l + 0-08A.z=2-67A, 



whence # = 9*2. After correction for the absorption of the 

 soft rays along the chamber, we obtain for relative ionization 

 produced by the soft rays from radium. B a value about 10'3; 

 this is in good agreement with the result obtained above by 

 direct measurement, using the soft y rays from radium D. 



The ionization in C0 2 and S0 2 , relative to air, was also 

 determined for the hard rays of radium D (/x = 0*99 cm. -1 Al). 

 It was found that in 00 2 the relative ionization was the same 

 as for the soft rays and equal to about 1*5, which is also the 

 density of G0 2 relative to air. With S0 2 in the ionization- 

 chamber the results were quite different and more compli- 

 cated. The initial ratio . — ^—~. — — ~~ was about 10 



ionization in air 



(after the usual correction required in the case of soft rays) ; 

 * Barkla and Simons, Phil. Mag. xxiii. p. 317 (1912). 



