3Q 



THE DIFFUSION OF GASES THROUGH 



gas mixture, here hydrogen and oxygen, and it is therefore not remarkable 

 that the final coefficients of the linear march are all specific of the mixture. 

 This fact is particularly borne out by the following phenomenon. On 

 May 7 to 8 the artificial atmosphere of hydrogen was accidentally replaced 

 by an atmosphere of air but for one day. The usual effect of an enormous 

 loss, continuing for a day thereafter, even though the atmosphere of hydro- 

 gen was replaced, is apparent (d to e in curve). After May 9 the period of 

 recovery begins, efflux and influx being at first about equal (e to /in curve). 

 The rapid loss on May 7 to 9, in response to the atmosphere of air on May 

 7 to 9, shows that the contents of the swimmer must have been largely 

 hydrogen gas. The prolongation of the effect for another day is probably 

 due to air in the water. Changes of rate are, as usual, abrupt. 



dJpr/3 



28dH(«/3 



Fig. 9. — Chart showing loss of mass of gas in diver in lapse of days. 

 Diffusion of oxygen into hydrogen. 



The period of recovery, however, is characterized by an entirely new rate, 

 viz, 



— m = 1 8 X io~ 6 g/day 



only a little more than one-half the preceding rate. Hence 



k = o. 44X10 



In other words, the new rate corresponds to a diffusion of three gases, 

 hydrogen, oxygen, and nitrogen, and is characteristic of this mixture. The 

 coefficient is the smallest observed, but the final period of steady diffusion 

 has not yet been reached. 



