Colour - Vision. By Captain W. de W. Abney. (Sampson Low, Marston,
and Co.)—This volume, contains the Tyndall Lectures, delivered at the Royal Institution in 1894. It deals scientifically with the subjects of Colour-Vision and Colour-Blindness, the latter being a matter of much practical importance in connection with the risks of railway and sea travel. (Captain Abney was a member of the Royal Society Committee on this subject.) The lectures are, of course, of a technical character, and cannot be discussed in these columns. We may mention an amusing anec- dote which is told d propos of the old name of Colour-Blindness. " Daltonism " (from the fact that the Chemist Dalton had this defect, and was, of course, helpful in making a scientific diagnosis of it). Dalton, as a Quaker, objected to a dress of scarlet. But when made a D.C.L. at Oxford, he wore the scarlet gown for several days in the streets, not knowing what the colour was.