ELECTRON METHOD OF STANDARDIZING CORONAS. 75 



67. Conclusion. Supposing the electron value to be io 10 e = 3.4 electro- 

 static units as before, the normal velocities of the ions in wet air to be 

 M = i.37, ^=1.51 cm. /sec. in the volt/cm, field, the coronal value of the 

 ions caught in the above fog chamber is in the several cases 



Total ions, 1,700,000 Total nuclei, 38 per cent. 



385,000 47 per cent. 



135,000 44 per cent. 



When N is 1,700,000 the coronas are too diffuse for sharp specification. 

 If it is assumed that negative ions only are caught, and if the nucleations 

 corresponding to the coronas seen in the given fog chamber be taken as 

 developed in my earlier work, then for N+N' = 1,700,000, 385,000, and 

 135,000, the electron values are io 1 V = 4-4, 3.6, and 3.9 electrostatic units. 



With regard to the two parts of this paper that need revision the first, 

 the comparison of the computed condenser capacity C' with a standard, 

 is a minor matter, but the other, i. e., the marked distribution of ioni- 

 zation along the axis of the fog chamber, will need further inquiry. In 

 the direction of the exhaustion the amount of ionization may vary in the 

 ratio of more than i to 2, in a fog chamber of about 0.5 meter of length, 

 and this under conditions where there should apparently be no variations 

 and irrespective of the production of radiation from within or from out- 

 side of the fog chamber. The final question relating to the drift, and the 

 asymmetry of the curves will be considered in all its bearings in the next 

 chapter. 



