ILLUSIONS OF COLOUR

Evening Star, Issue 22807, 16 November 1937, Page 11

ILLUSIONS OF COLOUR

SCIENTIST'S MAGIC A London professor from Bart’s, attending the British Association meeting at Nottingham, proved the biggest, draw of the conferences. Professor H. Hartridge filled the largest cinema in the town with a talk on “illusions of colour.” Having warned his vast audience that a great many of them would be unable to follow his experiments because they were colour-blind, he proceeded to perform tricks as good as any magician's. A dancer in a drab brown was transformed before their eyes into a butterfly creature radiating colour. An did man and woman, in red discovered the elixir of life in dumb show and he and his wife became young again and richly clad. The secret lay in the use of sodium lamps, which have a peculiar effect on the watching eyes. When white light was added all the colours were revealed as usual. Wimbledon and the four and a-half miles of Purley Way are lit up with sodium lamps, which increase _ the visual sharpness by cutting out irrelevancdes. They are a real economy in lighting. • MARVELLOUS DRUGS.

Professor Hartridge, for many years an outstanding expert on the eyes, described! two drugs which have queer effects on our colour sense. One is mescal, a vegetable compound beloved by American Indians. Ten minutes after using it, on closing the eyes, meet beautiful colours appear, and, after a time, assume human shapes with the most glorious raiments imaginable. Professor Hartridge said a Cambridge friend of his had some, but refused to part with it. He could not get any from America, as the Government had banned it.

Santonin, the other drug, is easily obtainable.

it is a yellow powder, and is used to kill worms in animals and children, its effect, which the professor described from personal experience—“l quite enjoyed it,” he said—was to make everything seem bright yellow for 24 hours.

• This was because it took away blue temporarily from the spectrum and left only red and green, which, in this scheme of things, is yellow. Santonin is harmless, and anyone can try it if they wish to do so.