Section III, 1918 [153] Trans. R.S.C. 



The Radioactivity of the Natural Gases of Canada 



By John Satterly, D.Sc.,F. R.S.C, and J. C. 

 McLennan, Ph.D.,F.R.S.C. 



(Read May Meeting, 1918) 



Introductory. The earliest account of any measurement of the 

 radioactivity of a Canadian natural gas appears in a paper by Pro- 

 fessor J. C. McLennan in 1904.^ He examined several natural gases 

 in the Province of Ontario and estimated their relative radioactiv- 

 ities. At that time there was no means of estimating the absolute 

 radium content but the fertile suggestion was made that since the 

 gas helium is one of the products of radioactive disintegration it w^as 

 likely that helium would be found to be one of the constituents of 

 natural gas. 



Since 1904 many investigators have published reports on the 

 radioactivity and helium content of natural gases in Europe and the 

 United States^ but up to the present only one "natural" gas in Canada 

 has been examined for radioactivity. In the same interval much 

 work has been done on natural mineral waters and the gases issuing 

 from such natural springs.^ 



In the spring of 1916 it was decided from reasons of both practical 

 and theoretical natures to make a systematic survey of the natural 

 gases of the whole of the Dominion, examining all the gases for their 

 radioactive and helium contents in the hopes of establishing relations 

 between these two factors and also possibly between these and the 

 nitrogen content. We may anticipate the result of the work by 

 saying here that no direct relation has been established between the 

 radioactivity and either the helium and nitrogen contents but that 

 helium and nitrogen usually v^ary together i.e., when one is high the 

 other is high. 



Collection and Testing of the Gases. With one exception all the 

 gases were collected in the field by Professor McLennan and great 



^Proc. International Electrical Congress, St. Louis, 1904. 



^Moureau and Lepape. Comptes Rendus, p. 598, 1914. Cady and McFarland. 

 Journ. Amer. Chem. Soc. Vol. XXIV, p. 1523, 1907. 



^Satterly and Elworthy Mineral Springs of Canada. Bulletin No. 16 of the 

 Bureau of Mines. Parts I and II. (Bibliography on p. 54 of Part I). Also Satterly 

 and Elworthy "The Radioactivity of Some Canadian Mineral Springs" Roy. Soc. 

 Canada, 1917. Vol. XI and Elworthy — Examination of the Hot Springs at Banff, 

 Alberta. Trans. Roy. Soc, Canada 1917, Vol. XI. 



