290 
PHYSICS: LEMON AND BLODGETT 
It is important to note that in no case does the final pressure of a mixture 
fall as low as the sum of the final pressures of the two components when ad- 
sorbed separately. In other words, each component in the mixture hinders 
the adsorption of the other. This is not in agreement with an earlier paper 
by Bergter^ who concludes that "in the range of pressure investigated the 
ability of charcoal to adsorb nitrogen must be increased by the presence of 
oxygen." Bergter's pressure range was entirely below 1 mm. and the dis- 
crepancy may be due to this difference of experimental conditions. 
In the course of the work it became of importance to know if the final ad- 
sorption would be the same if a given amount of pure gas were adsorbed all 
at once as it would if half were adsorbed at one time and then the second half 
admitted later. It was found that adsorption is much more complete in the 
second case, the quantitative pressures being as follows: 
Final 
Pressure Log p 
a— Oxygen 100 per cent 0 . 00797 7 . 902-10 
b— Oxygen 50 per cent, 50 per cent 0 . 00604 7 . 781-10 
a— Nitrogen 100 per cent 1 . 86 0 . 270 
b— Nitrogen 50 per cent, 50 per cent 0 . 649 9 . 812-10 
In adsorbing equal parts oxygen and nitrogen it seems to be immaterial 
which is admitted first, the final pressure being within experimental limits the 
same. 
Oxygen 50 per cent. Nitrogen 50 per cent 0 . 045 1 8 . 654-10 
Nitrogen 50 per cent, Oxygen 50 per cent 0 . 0481 8 . 682-10 
Oxygen and nitrogen mixed each 50 per cent 0 . 0924 8 . 966-10 
