On the Spectrum of the Lightning
Koiwai, M.
Abstract
 The spectrum of the light from the night sky of often shows unusually predominant band at about λ6520Å(Fig. 1). This band is too intensive to ascribe to the light of the night sky and the author suspects it to be the light from the lightning. To make sure of it, he has observed the spectra of the lightning in the summer 1940.
In this paper he reports the wave-lengths and characters of the spectrum of the lightning and compares the spectrum with the spark and low pressure discharge spectra in laboratory.
He identifies the lines and bands with the most probable element in the air.