JoLY AND Smyth — Amount of Radium Emanation in the Soil. 161 



the effects of adding radioactive materials to soils upon which wheat was raised. 

 These results are positive, but they leave some uncertainty as to tiie actual 

 nature of the influences at work. 



Whether the exhalation of radioactive gases from the soil in a district 

 influences the well-being of the higlier organisms which inhabit it remains 

 to be ascertained. The physiological and pathological influences of radioactive 

 emanations are only beginning to be studied. 



Description of Chart (Plate IX.). 



The numbers on tlie vertical axis are to be multiplied by 10"'^ Where 

 the quantities dealt with are too large, the further multipliers 10 and 100 

 must be applied, as marked on the particular curves. The lighter-drawn 

 curves refer to the emanation in one litre of ground-gas ; the heavier 

 curves to the emanation escaping in an hour from one square metre, 

 i.e. the amount exhaled. 



