Evans found that the 4686 series and the Pickering series can be obtained in a helium spectrum showing no trace of the ordinary hydrogen lines. These series were observed a few years ago by Prof.

WITH a long hydrogen tube, viewed end on ... forming the first two members of a new series.

Hot gases don’t produce a continuous emission spectrum. Black hydrogen absorption lines are at the same wavelength as the bright hydrogen emission lines. Key fact Line emission spectra are ...