340 



Mr. W. B. Haines on 



with charcoal before the measurements. The changes which 

 take place in the ions are very large, as will be seen by a 

 reference to figs. 1-3, which show some typical results taken 



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in the manner described. In its initially pure state the gas 

 gives an ionic current for very low voltages, and (in those 

 cases where the readings are completed before the conditions 

 change appreciably) the curve is quite smooth over a large 



