784 



Mr. J. Satterly on the Absorption of 



absorb more and more water, and thus its absorbing qualities 

 for other gases might gradually diminish. Experiments were 

 now made to test this point. The (silica) tubes A and B 

 were placed in parallel, and air-streams of the snme strength 

 ('5 litre per minute) were passed through each. The humidity 

 o£ the air going to the separate tubes was altered as sho vn in 

 Table II. In the first three experiments the source cf emana- 

 tion was the air ; in the others this source was supplemented 

 hv bubbling the air through a radium solution containing 

 j or 3'14: x 10" 9 gm. radium. The duration of the exposuie 

 was about 21. hours in each case. 



Table TT. 



Tube A. 



Outer air, humidity unaltered 



Outer air, dried by calcium chloride, 

 then bubbled through 6 in. water. 



Outer air, humidity unaltered 



Laboratory air bubbled through the 

 solution i 16" 



g b 



1-5 



1-4 



•9 



Outer air bubbled through the solu- 

 tion 



Outer air bubbled through the solution 



and th( 



•ied bv calcium chloride 



Outer air bubbled through the solution, 

 then dried by calcium chloride, 

 then saturated, by passing through 

 100 cm. wet cotton-wool. 



Outer air bubbled through the solution, 

 then dried by calcium chloiide 



6-8 



7-8 



7-3 



11- 



Tube E. 



Outer air bubbled through 6 in. water 



Outer air dried by same calcium chlo' 

 ride as used with A 



Outer air sent through 40 cm. wet 

 cotton-wool. 



Laboratory air bubbled through the 

 solution and sent through 100 cm. 

 of wet cotton-wool. 



Outer air bubbled through solution 

 and then dried by calcium chloride. 



Outer air bubbled through the solu- 

 tion 



Outer air bubbled through the solu- 

 tion, then dried by same calcium 

 chloride as used with A 



Outer air bubbled through the solu- 

 tion, then dried by same calcium 

 chloride as used by A, then satu- 

 rated by passing through 100 cm. 

 wet cotton-wool. 



a 



1-6 



1-5 



11 



18-7 



9-2 



70 



9-2 



139 



From these results it is clear that, allowing for the fact 

 that under the same conditions tube B nearly always absorbs 

 about 10 per cent, more emanation than tube A, the amounts 

 c£ emanation absorbed in my experiments by the charcoal 

 are independent of the humidity of the air carrying the 

 emanation. 



