Societies and Academies

Abstract

LONDON. Royal Society, November 25.—Sir Archibald Geikie, K.C.B., president, in the chair.—Sir W. de W. Abney: The change in hue of spectrum colours by dilution with white light. The author shows that by diluting the spec trum colours from the red to the green-blue with moderate percentages of white light, their hue travels towards the yellow, the change being dependent on the amount of red and green existing in the white added. At a point near γ 5780 the hue remains unaltered by the addition of white, and it is towards this point in the spectrum that the colours on each side of it travel. It is pointed out that this change in hue enables the relative amounts in green and red from γ 5000 to γ 6000 to be accurately determined.—Prof. G. E. Hale and F. Ellerman: The nature of the hydrogen flocculi and their structure at different levels in the solar atmosphere.—Prof. H. L. Callendar and H. Moss: The boiling point of sulphur corrected by reference to new observations on the absolute expansion of mercury.—C. Cuthbertson and Maude Cuthbertson: The refrac tion and dispersion of neon. The refractivities of neon (Ne2) for different wave-lengths are found experimentally to be