68 



THE DIFFUSION OP GASES THROUGH 



same as that of water. The solution may therefore be regarded as holding 

 20.8 grams of KCl in loo grams of water, or 17.2 grams of salt in 100 grams 

 of solution. To obtain the vapor pressure iv' of the moist air above the 

 solution, it was at first assumed that the reduction of vapor pressure at 18° 

 was relatively the same as at 0° C. for a given strength of solution. Further- 

 more, that the case of KCl would be practically identical with the case of 

 brine. Afterwards (using Landolt and Boernstein's tables) it was found 

 that such an assumption is inadmissible and that the equation should be 



Table 24. — Air-air through KCl solution (20.8 grams in 100 grams water). Vessel 

 B (single tube). ^7=37.425 grams; C= 134.43; P(7 = 2.47o; float, 2^ = 3.8 cm.; 

 vessel, 2r=5.8 cm. P2a= i.i 133 at 24.5°. 



Fig. 22. — Chart showing loss of standard volumes 

 of gas in diver in lapse of days. Diffusion 

 of air through KCl solution. 



7r' = 7r(i —0.086) for KCl. Hence these data for KCl in the table must be 

 corrected before the diffusion coefficients are computed, as follows : The 

 error of it' being 57r' = o.o297r, its effect on I'o will be 



This correction is to be supplied in the summary. For brine, by graphic 

 interpolation, using either Dieterici's or Smits's observations, the correction 

 is 7r' = 7r (i— 0.115), and this is provisionally used in table 24 and fig. 22. 



