190 PHENOMENA, ATOMS, AND MOLECULES 



TABLE XVII 



Comparison of Observed and Calculated Values of Wb 



Low Pressures 



P - 0.015 mm. P - 0.039 mm. P = 0.207 mm. P - l.I mm. F = 4.4 mm. 



Wi>. W£). Wd. Wo. Wo. 



Tj. Obs. Cal. Obs. CaL Obs. Cal. Obs. Cal. Obs. Cal. 



i8oo 0.007 0.022 0.019 0.037 0.068 0.083 O.II 0.17 0.22 0.24 



2000 0.025 0.066 0.09 O.I16 0.27 0.27 0.54 0.58 0.71 0.85 



2200 0.085 0.124 0.20 0.25 0.65 0.64 1.45 1.44 2.10 2.31 



2400 0.139 0.162 0.35 0.38 1. 17 1. 12 3.13 2.82 4.95 4.95 



2600 0.179 0.176 0.45 0.44 1. 71 1.49 5.00 4.4 9.8 9.0 



2800 0.180 0.179 0.47 0.46 1.85 1.69 6.4 5.8 



TABLE XVIII 



Comparison of Observed and Calculated Values of Wd 



Higher Pressures 



values of To used in the calculations were those given in Tables IX, XI and 

 XII. At pressures of lo mm. and more, To was taken equal to T2. The 

 coefficient F was calculated for each temperature and pressure by sub- 

 stituting the values of B and E from (68) and (54) into Equation 42. 



The values of W/? have thus been calculated directly from the dis- 

 sociation constant, the diffusion coefficient, and the coefficients ai and 02. 

 An examination of Tables XVII and XVIII shows that the agreement is 

 on the whole excellent ; so good, in fact, that it would seem to show not 

 only that we are dealing with a real dissociation of hydrogen into atoms, 

 but that our theory of the mechanism of the process is substantially correct. 



GENERAL DISCUSSION 



The theory which has been used in the presen1*^aper was only developed 

 after several attempts had been made to calculate the degree of dissociation 

 by other methods. Each of these other methods, however, seemed to lead 



