156 THE ROYAL SOCIETY OF CANADA 



and carbondioxide. The leak was 1-12 times that observed with air. 

 This figure is therefore used to reduce the leak observed in this gas 

 to give the leak that would have been produced in air by the same 

 amount of emanation.^ For other gases of known compositions the 

 reducing factor can now be calculated, or, of course it can be re- 

 determined with each sample. 



Results. The following table gives the results. The radium 

 emanation content is expressed in terms of radium, the quantity of 

 radium quoted being that which would be in equilibrium with the 

 radium emanation in a litre of gas. 



For convenience the gases are listed geographically. 



In a larger paper which will be published in due course the full 

 particulars of these fields, including a description of the country, 

 the geological formations, the logs of the wells, the yields of gas, the 

 pipe lines in operation, etc., will be given. 



iSee also Metcalfe. Phil. Mag., 1909. 



