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THE ROYAL SOCIETY OF CANADA 



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29-7 



The Wulf elect ronieter was placed out of doors near the tennis 

 court stands on the College Campus. The subsoil was Saxicava Sand 

 with low radium contents (0-2 X 10—^^) grammes of radium per gramme 



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of rock. The surface soil was thin, and its radium contents were not 

 tested, nor were the thorium contents of the soil or subsoil known. 

 The testing vessel was of copper 2 mm. thick, carefully cleaned, 31 cm. 

 high, 17 cm. in diameter, about 7 litres in volume, and although the 

 electric capacity was high, the readings were remarkably reliable, and 



