A note on the absorption of the green line of thallium vapour

Investigations on the structure of spectral lines indicate that lines of heavy metals like mercury and bismuth are generally complex in structure. The constitution of mercury and bismuth lines has been studied by several physicists, who have established the complexity of these lines. Recently Metcalfe and Venkatesachar described a series of interesting experiments on the absorption ofλ 5461 by luminous mercury vapour, where it was found that all the satellites of the green line were strongly absorbed under suitable conditions and that the ratio of emission to absorption was fairly constant for all lines except — 0.237 A. U.