82 



THE DIFFUSION OF GASES THROUGH 



(i —0.255). The curve obtained for the progress of diffusion is a line nearly 

 horizontal, showing a liquid all but impervious so far as the air molecule is 

 concerned. The slopes of the curve, table 42, fig. 35 a, correspond to 



t'o = 0.00125 c.c. day or 10^^ = 0.045 



the smallest value thus far obtained. Though a comparison with AICI3 

 is intended, it must be remembered that the apparatus is the one with the 

 long diver and liable to show relatively small results. 



Table 42. — Air-air through FeCIs solution (37.5 grams in 100 grams water). Vessel H 

 (single tube). p,^= 1.2510 at 22°. Constants as in table 23. 



B 



Jan.H 



Fig. 35 A, E. — Charts showing loss of standard volumes of gas in diver in lapse of days. 



Diffusion of air through FeCls solution. 



62. The Same, Continued. — The preceding solution was now diluted 

 with an equal bulk of water. The density was thus reduced to 1.1260 at 

 24°, corresponding to about 14.3 grams in 100 grams of solution or 16.7 

 grams in 100 grams of w^ater. Thus the provisional vapor pressures are 

 7r' = 7r(i —0.095). The record of results is contained in table 43 and fig. 35 b. 



Table 43. — Air into air through FeCU solution (16.7 grams in 100 grams water). 

 Vessel i7. Constants as in table 42. p,t,= 1.1260 at 24°. 



The rates of diffusion correspond to 



z'o = 0.00275 c.c./day or io^'\ = 0.094 



Observations were taken but once a wxek with an obvious advantage 

 to the smoothness of the curve. The ratio is here remarkably linear. 



