254 



Taylor — Ionization of Different Gases by the 



the total area under this theoretical curve is a measure of the 

 total ionization produced by the alpha particle in the gas. If 

 A t represents the area under the theoretical curve, then 



'•=/' 



I dx 



= 3/2 c(r)7i = 7'33 c 



(■;' being equal to 10'8 centimeters). Heuce c is 3/22 of the 

 area under the theoretical curve when the average range of 



Table I. 



Gas or 

 Vapor 



c 

 or area under 

 theoretical 

 curve divid- 

 ed by 7-33. 



Area un- 

 der expe- 

 rimental 

 curve as 

 measured 

 with plan- 

 imeter. 



Ratio 

 of area 

 under ex- 

 perimen- 

 tal curve 

 toe. 



Ratio of the total ioni- 

 zation in the gas to 

 that in air. 



Taylor. Bragg. 



Relative 

 energy re- 

 quired to 

 produce an 

 ion. 



Air 



11-24 



980 



87 







1-00 



H, 



10-00 



966 



96 



0-99 



1-00 



1-01 



CH 3 I 



14-7H 



1301 



88 



1-33 



1-33 



075 



CH 4 



12-65 



1156 



91 



1-18 





0-85 



C.H.C1 



14-05 



1251 



89 



1-29 



1-32 



0-77 



cs, 



15-60 



1355 



87 



1-38 



1-37 



0-73 



Air 



14-64 



1249 



85 







1-00 



N, 



13-81 



1206 



87 



0-96 



0-96 



1-04 



CO, 



15-01 



1262 



84 



1-01 



1-08 



0-99 



o, 



16-72 



1415 



85 



1-13 



1-09 



0-88 



C 4 H 10 O 



19-42 



1702 



88 



1-36 



1-33 



0-74 



Aii- 



13-27 



1182 



89 







1-00 



SO, 



15-30 



1223 



80 



103 



.. 



0-97 



HCl 



17-70 



1530 



86 



1-29 







0-77 



HBr 



18-32 



1527 



83 



1-29 



-- 



0-77 



Air 



13-36 



1190 



89 







1-00 



HI 



17-68 



1535 



87 



1-29 



-- 



0-77 



the alpha particle is 10 - 8 centimeters in any gas whatever. 

 The values of c recorded in column 2 of Table I are then 3/22 

 of the area under the theoretical ionization curves in the 

 respective gases. 



The areas under the ionization curves being proportional to 

 the energies consumed in the production of ions in the respec- 

 tive gases, the value of c in any one gas depends upon the total 

 ionization produced in the gas, and consequently upon the 

 energy required to produce an ion in the gas. Then the ratio 

 of the area under the experimental curve to c should be a 

 constant. By dividing the areas under the experimental 



