LIQUIDS AND ALLIED EXPERIMENTS. 



81 



Table 40 and fig. 34 a record the results. The diffusion in the main 

 proceeds in accordance with 



v Q = 0.0070 c.c./day or io 10 /c = 0.168 



and the rates finally obtained are 



i = 0.0095 c.c./day or io 10 k = 0.229 



The usual difficulties in relation to equilibrium conditions assert themselves 

 at the outset. 



30 Skc. 5 



Fig. 34 a, b. 



-Chart showing loss of standard volumes of gas in diver in lapse of days. 

 Diffusion of air through Na 2 S04 solution. 



60. The Same, Continued. — Diluted with about an equal bulk of water 

 the density of the solution fell to p= 1.0580 at 21°, corresponding to 6.32 

 grams in 100 grams of solution or 6.75 grams in 100 grams of water. The 

 vapor pressure is 7r' = 7r(i —0.014). 



Table 41. — Air into air through Na 2 S0 4 solution (6.75 grams in 100 grams water). 

 Vessel E. Constants as in table 40. p w = 1.0580 at 21 °. 



Date. 



Barom- 

 eter. 



t 



// 



»o 



Date. 



Barom- 

 eter. 



t 



// 



t'o 



Dec. 26. . 



77.10 





 17.1 



70.46 



5.864 



Jan. 3.. 



73.98 



O 



17.9 



69.48 



5.767 



28.. 



75 -50 



17. i 



69.96 



5.822 



10.. 



77-35 



17-5 



68.58 



5.701 



30. . 



75-74 



17.3 69.70 



5.796 



17.. 



76.54 



17.2 



68.08 



5.664 



31.. 



76 -34 



17.4 69.68 



5-793 



24. . 



76. 10 



17.6 



67.68 



5.624 



Jan. 1 . . 



76.01 



17.7 69.54 



5.776 



31. . 



76.17 



17-5 



67.30 



5-594 



2 . . 



76.87 



17.8 69.42 



5-764 













The observations are given in table 41 and fig. 34 b. They are reasonably 

 regular and show that the weekly period of observations is in every way 

 preferable to the daily period. The rates of diffusion are 



t'o = 0.0065 c.c.day or io 10 k = 0.164. 



which is still far below the value for pure water, in spite of the dilution of 

 the solution in question. 



61. Diffusion of Air into Air Through FeCf 3 Solution. — A nearly con- 

 centrated solution of this very soluble salt was prepared, showing the density 

 1.25 10 at 22 and corresponding to 27.3 grams in 100 grams of solution, or 

 37.5 grams in 100 grams of water. A table for the vapor pressures above 

 the solution could not be found. The data for CaCl 2 were, therefore, provi- 

 sionally adopted, as the effect upon k is not relatively large, when compared 

 with the other inevitable errors. Hence the vapor pressures are ir' = r 



