[BOYLE] TEMPERATURE AND VELOCITY OF GAS CURRENT 105 
emanation had to wind through a long tube of small cross-section rather 
than through a short tube of large cross-section, even if the quantity 
of charcoal were the same in both cases. Following is the result of an 
experiment to test this point. 
Curves I, I, and III, fig. 9, table 4, correspond to three tubes of 
diameters 6, 12, and 25 mm., respectively, (areas 1 : 4 : 27), each con- 
taining 5.86 gms. of charcoal. With an exception at the lowest speeds 
of air current, the curves I and II are almost identical. III differs a 
little from I and II at medium speeds, and coincides with them at the 
high, but at the lowest»speeds the variation is considerable. Reference 
will be made to this later. 
100 



20 
T nesonr TION OF EMANATION. 
oO 


+ © + -8 12 /-6 2.0 2.4 2.8 
FLOW IN CC PER SEC. 
Fic he: 
Effect of Temperature on the Absorption. 
Since the temperature of the cocoanut charcoal influences in a 
remarkable degree the absorption of other gases, it is natural to suppose 
that it will also have an effect on the absorption of the emanation. 
To determine this point experiments were carried out at four temper- 
atures of the charcoal, 210°, 100°, 21°, and —78° C., the temperatures 
of hot oil, boiling water, air of the room, and a mixture of solid carbon 
dioxide and ether respectiveiy. The quantity of cocoanut charcoal 
used for the experiments was 2-9 gms. 
