818 



Dr. R. W. Boyle 



on the 



siopcocks is to some extent an absorbent o£ the emanation, 

 but the extremely small amount of it exposed to the emanation 

 in these experiments could not have been the cause of any 

 appreciable error. 



On the whole the accuracy expected was about 1*5 per 

 cent., and this is about the range of agreement shown in the 

 results given later. 



The tact that the emanation produces small quantities of 

 hydrogen and oxygen by its action on water, and that the 

 a. rays produce ozone, should not affect the results. It will 

 'be shown that the nature of the gas, or mixture of gases, 

 holding the emanation has no effect on the coefficient, at 

 least within the experimental error. It might be remarked 

 that when air or oxygen was used as holder of the emanation 

 there was a very strong odour of ozone on opening the 

 bulbs. 



In the different experiments with distilled water, the 

 results of which now follow, the ratio of volume of water to 

 volume of gas within the mixing bulb varied between 0'5 

 and 2'5. 



Results. 



(1) On Henry s Law. 



The experiments to show the constancy of the coefficient 

 of solubility were carried out at 14° C, using air as the gas 

 holding the emanation. 



It was found that with the same pressure of air but 

 different concentrations of emanation, or with different 



Table I. 

 Temperature 14° C. 



1 



Pressure of containing 

 Gas in cm. Hg. 



Concentration. 



Emanation per c.c. 



of gas. 



Coefficient, 



of solubility. 



183 



1"81 millicuries * 



0-301 



145 



0-076 



0-299 



81-6 



041 



0-300 



76-0 



1-44 



0-300 



62-0 



0-017 



309 



36-8 



021 



0-303 



14-7 



0-20 



0-307 



9-0 



0-041 



0-302 



* TOie curie is defined (following the suggestions of the Brussels 

 Conference) as the quantity of emanation in radioactive equilibrium with 

 one gram of radium element. One millicurie is 1/1000 of this unit.] 



