Sir William Bragg, O.M., K.B.E., F.R.S.
Many of the colours of Nature depend on the use of 'dyes'. One of the most universal of these is chlorophyll, which is responsible for the green of vegetation. The colours of flowers depend mainly on a class of natural dyes called 'anthocyanins.' The colours of the sky and the haloes round the moon are caused by fine particles floating in the air, or by the molecules of the air itself.
This is a synopsis of Sir William Bragg's talk tonight.