20 



THE DIFFUSION OF GASES THROUGH 



least squares. The run of the thermometer on the same sheet, fig. 6, bears 

 out this surmise. The barometer, like the vapor pressures, shows no easily 

 discernible relation to the weight curve; but the run of temperature fore- 

 shadows the kinks in the m curve throughout its extent. 



3^e(>. 5 iO 15 20 Z^JiatZ 7 1Z m Zl Z7 Jlpvi 6 11 

 Fig. 6. — Loss of mass of gas in diver in lapse of days. Diffusion of air into air. 

 If we write for the air-water system (time t in days, mass m in grams) 



m = Wq — mt 

 and compute the constants pIq and in by the method of least squares from 

 the 68 observations made between January 31 and April 11, the values 

 obtained are 



Wo = 0.0085327 gram w = 0.00003493 gram/day 



