Solubility of Radium Emanation. 853 



Conclusion. 



Within the limits of experiments previously stated, it is 

 found that in the case of radium emanation Henry's law is 

 valid. In comparison with many ordinary gases the emanation 

 may be considered fairly soluble. 



It is interesting- to compare the solubility of the emanation 

 in water with that of some common gases, adopting the same 

 definition of the coefficient of solubility as above. The 

 following table shows approximate values which refer to the 

 condition of an atmosphere of the gas in question pressing 

 on the surface of the absorbing liquid. The temperature 

 chosen is 14° C. 



Gas. Coefficient of solubility. 



Hydrogen 0*02 



Nitrogen 0*02 



Oxygen O'Ot 



Ethylene 0*17 



Nitric oxide 028 



Nitrous oxide 0*81 



Carbon dioxide 1*1 



Sulphuretted hydrogen 3*3 



For emanation, the coefficient at 14° 0. is 0*303, and it 

 decreases from 0*507 at 0° to 0*153 at 40° C. 



At 14° C. a quantity of emanation will distribute itself 

 between equal volumes of water and a gas so that about one- 

 quarter will go to the water and three-quarters to the gas. 

 At 0° C. one-third will go to the water and two-thirds to 

 the gas. 



Of the other liquids examined it is found that mercury 

 does not absorb the emanation, and that sea-water of specific 

 gravity 1*022 at 14° (J. absorbs about 0*84 times as strongly 

 as water. Organic liquids absorb very strongly. At 14° 0. 

 ethyl alcohol (absolute) absorbs 24 times, amyl alcohol 31 

 times, and toluol 45 times as strongly as water. 



The interest of experiments such as the above is not 

 confined entirely to considerations of radioactivity. The 

 experiments described were performed on a gas at partial 

 pressures of from 8 x 10" 4 to 8 x 10" 6 mm. Hg, and it was 

 found that under these conditions one of the ordinary gas 

 laws holds good. At these extreme tenuities, researches on 

 the ph}-sical and physical-chemical properties of gases by all 

 other methods are barred to us by experimental limitations. 



P/iil. Mac. S. G. Vol. 22. No. 132 Dec. 1911. 3 L 



