Burristead and Wheeler — Radio-active Gas. 



105 



porous plate ; the time is counted from the removal of the 

 plate. As before, the readings are reduced to the same scale, 

 the mean of four readings just before the plate was removed 

 being taken as 100. 



Earth-Gas. 



Time in 



Observed 



Plotting 





Time in 



Observed 



Plotting 



minutes. 



ionization. 



Scale. 





minutes. 



ionization. 



Scale. 



o-o 



2*81 



100- 





79-5 



1-62 



57-7 



2-5 



2-81 



100- 





100-5 



1-52 



54-1 



8-0 



2-68 



95-4 





115-5 



1-26 



44-9 



13-0 



2'70 



96-1 





130-5, 



1-12 



39-9 



18-0 



2-60 



92-5 





145-5 



0-93 



33-1 



24-0 



2*42 



86-1 





1605 



0-82 



29-2 



30-5 



2-39 



85-1 





175-5 



0-67 



23-8 



40-5 



2-28 



81-1 





190-5 



0-59 



21-0 



50-5 



2-06 



73-3 





205-5 



0-49 



17-4 



60'5 



2-00 



712 















Eadium Emanation. 







Time in 



Observed 



Plotting 





Time in 



Observed 



Plotting 



minutes. 



ionization. 



Scale. 





minutes. 



ionization. 



Scale. 



o-o 



12-98 



100- 





59-0 



8-92 



68-7 



4-0 



12-43 



95 8 





64-0 



8-32 



641 



8-0 



12-08 



93-1 





69-0 



7-26 



55-9 



11-0 



12-20 



94-0 





74-0 



8-04 



61-9 



17-0 



11-47 



88-4 





102-0 



6-38 



49-1 



21-0 



11-26 



86-7 





uo-o 



5-52 



42-5 



26-0 



10-99 



84-7 





115-0 



5-72 



44-1 



3l'() 



10-61 



81-7 





119-0 



5-28 



40-7 



37-0 



10-44 



80-4 





226-0 



1-84 



14-2 



50-0 



9-34 



71-9 





230-0 



1-72 



13-3 



54-0 



9-14 



70-4 





235-0 



1-64 



12-6 



The following table taken 



from 



the curves gives a 



compari- 



son of the two gases 



j 















Diffusion. 







Tim€ 



s in minutes. 



Earth-Gas. 



Radium Emanation. 





20 





90- 





87-6 







40 





80-2 





76-6 







60 





70*6 





66-0 







80 





60-5 





56-9 







100 





51-8 





48-5 







120 





43-6 





412 







140 





36-0 





34-6 







160 





29-4 





28-8 







180 





23.8 





23-7 







200 





18-9 





19-3 







220 





T14-5- 



* 



15-8 







240 





[11-0] 



* 



12-0 









*Es 



trapolated. 







