The Stark effect in the molecular spectrum of hydrogen.

So far as atomic spectra are concerned the study of the Stark effect may be said to be well established both theoretically and experimentally in most of its fundamental features. The equivalent ls not true in the ease of molecular spectra, for our knowledge of the effect of an external electric field upon a radiating molecule is at best only very meagre. This state of affairs is due largely to the fact that many atomic spectra exhibit large Stark displacementa in electric fields of the magnitude easily obtained in experiment, whereas most of the attempts to detect similar effects in band spectra have yielded negative results. [...