1. A formula is derived by which accurate corrections allowing for the distribution of velocities of the impacting electrons may be applied to the observed values of the radiating potentials. 2. Measurements on nitrogen revealed- (a) a very strong effect at 8.29 +/- 0.04 volts. (b) a very doubtful effect at 7.3 volts. (c) an effect appearing only at lower pressures but strongly at 6.29 +/-.06 volts. 3. These results are explained as follows: (a) The wave-length λ corresponding to 8.29 +/-.04 is 1490.7 +/- 10 and this effect is, therefore, identified with the doublet found by Lyman at 1492.8 and 1494.8. (b) This gives λ=I700 and may be identified with the second doublet 1742.7 and 1745.3 attributed to nitrogen but by some thought due to silicon. (c) The value λ=I965+/-20 from 6.29+/-.06 volts is taken to correspond to the beginning of the band spectrum at 1870.9. The discrepancy is attributed to the presence of nitrous oxide. According to another theory the effect at 6.29 is considered due to lines in the region 2,000-3,000 A.U. coming from neutral atoms. The value 6.29 in this case is taken as the speed necessary before the electrons can split up the molecules. 4. From 3 (a) assuming line spectra to come from atoms, we have as an upper limit to the heat of dissociation of a gram molecule of nitrogen 190,000 calories. From the second theory in 3 (b) we have as a possible actual value for this heat of dissociation 145,000 calories. 5. Qualitative evidence was obtained supporting Davis and Goucher's discovery of true ionization in the neighborhood of 18 volts.