LIQUIDS AND ALLIED EXPERIMENTS. 



25 



or about 13.5 times the normal viscosity of hydrogen. Correcting as in §24, 

 the factor becomes 15, which does not agree with the corresponding datum 

 for air (about 13 times) as well as the values found above appeared to 

 predict. 



Fig. 7. — Chart showing loss of mass of gas in diver in lapse of days. 

 Diffusion of hydrogen into hydrogen. 



21. Transpiration of Imprisoned Air into Hydrogen Through Water. — 



The immediate use of equation (i) is inadmissible, since the gas constant R 

 varies, as the gas within the swimmer changes its composition. But since 

 at a given pressure and temperature Rp is constant for all mixtures, 



m = vp- 



Mgp, 

 R 



-(---) 



r \Pu, Py 



is still the correct value, relatively to volume, as intimated above. It is 

 merely necessary, therefore, to coordinate the correct value of p for the 

 initial gas and its gas constant R, after which the equation is applicable to 

 all subsequent gas mixtures, if the diffusion k by volume is to be computed ; 

 but m is now merely an apparent rate, and k merely a transitional value. 



