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ROYAL SOCIETY OF CANADA 



TABLE X. 



The results of these measurements are given in Table X. From 

 the numbers given in Table X it will be seen that although the ionisa- 

 tion currents were increased over thirtyfold, the ionisation and con- 

 sequently the secondary radiation produced by the gamma rays 

 from the radium was invariably less when the salt was in the cylinder 

 than it was before the salt was introduced. 



In as much as the ordinary or spontaneous ionisation in the 

 cylinder was found to be increased approximately twofold by the 

 introduction of the salt, it is clear, in the light of the numbers given 

 above that this increase in the conductivity was due to a primary 

 activity possessed by the salt, and not due to a secondary activity 

 imparted to it by the influence of external radiations, 



VII. Miscellaneous Experiments, 



With a view to ascertaining whether the activity of potassium 

 salts arose from the presence in the salts of traces of any of the active 

 elements, radium, thorium, or actinium, an attempt was made to drive 

 ofî any emanation which they might contain by raising the salts to 

 moderate temperatures. Although a number of the salts was treated 

 in this way, with none of them, however, was the slightest indication 

 obtained of a loss of activity such as should accompany the expulsion 

 of radioactive gases. 



Although these experiments made it evident that the activity 

 was not due to the presence of traces of the elements radium, thorium 

 and actinium, or of their immediate products, in the salts, it was still 

 possible that the activity might be due to the presence in minute 

 quantities of uranium or of one of the active products of slow decay 



