Paper, 'On the crimson line of phosphorescent alumina' by William Crookes Crookes writes: 'In a paper which I had the honour of communicating to the Royal Society in March, 1879, I described the phosphorescence of alumina and its various forms when under the influence of the electrical discharge in vacuo, in the following words:—"Next to the diamond, alumina in the form of ruby is perhaps the most strikingly phosphorescent stone I have examined.' Annotations in pencil and ink throughout. Includes two diagrams of spectra. Subject: Chemistry / Spectroscopy Received 30 December 1886. Read 13 January 1887. A version of this paper was published in volume 42 of the Proceedings of the Royal Society as 'On the crimson line of phosphorescent alumina'. 1886