Residual Ionization in Gases. 



423 



In all these experiments care was taken to dry and niter 

 all the gases thoroughly before passing them into the ioniza- 

 tion-chamber. The hydrogen was prepared by allowing 

 dilute sulphuric acid to act on granulated zinc in a Kipp 

 apparatus. The carbon dioxide was taken from a cylinder 

 of the product usually sold commercially. The nitrous 

 oxide was also taken from a cylinder of the gas prepared 

 commercially for the use of anaesthetists. The ethylene 

 used was prepared by gently heating in a flask a quantity 

 of pure white anhydrous phosphorus pentoxide to which a 

 small quantity of absolute alcohol had been added, and the 

 acetylene was prepared in the usual way by allowing water 

 to act on calcium carbide. 



Readings were repeatedly taken during the past winter 

 with all the gases under the various conditions described, 

 and the final results compiled from all of these readings are 

 recorded in Table II. 



Table II. 



The number of ions generated per c.c. per second. 



Gas. 



Column 1. Column 2. 



Column 3. 



Column 4. 



Column 5. 



Column 6. 



Drop in 

 ionization. 



Alpha Beta 

 ray?. rays. 



Gamma 

 rays. 



Natural 



ionization in 



laboratory. 



.Residual 



ionization on 



ice of lake. 



Air 



2604 

 209-4 

 1460 

 2961 

 202-1 

 3046 



347-8 

 541-8 

 55-3 

 518-4 

 523-5 

 4530 



2070 

 3250 

 32-7 

 3060 

 3204 

 277-8 



8-66 



990 



1-96 



12-10 



10-70 



27-9 



4-38 

 4-83 

 Ml 

 6-32 

 502 

 2700 



4-28 

 507 



•85 

 5-78 

 568 



•90 



Carbon dioxide... 

 Hvdrogen 



Ethylene 



Nitrous oxide ... 

 Acetylene 



The values recorded represent the number of ions generated 

 per c.c. per second in the ionization-chamber of the electro- 

 meter under the different conditions mentioned, assuming the 

 ionic charge to be 4'65 X 10" 10 e.s.u. Under the heading of 

 "alpha ra\s," "beta rays,'' and " gamma rays," the numbers 

 represent the increases in the value of q for the different 

 gases when traversed by the respective types of rays. 



The final column headed "Drop in Ionization " contains 

 numbers representing the differences in the values obtained 

 for " q" under natural ionization in the laboratory and on 



