THE OSTWALD SYSTEM OF COLOUR HARMONY ARTHUR B. ALLEN Colour is sensation. The translation by the brain of sensations received by the eye imply psychological properties of the mind in relation to its surroundings. The psychological interpretation of colour is the keynote of the Ostwald theory. DEVELOPMENT WITHIN THE WORLD OF COLOUR FOLLOWS a twofold track. There is the one route which shows the gradual expansion of the palette of the artist, and there is the other route which shows the artist and the colour-scientist striving to formulate a system of colour classification and colour usage whereby the maximum results may be obtained in the shortest and the most accurate manner. So colour science has always had its place in the life of the professional artist, for he sees in the findings of the colour scientist the raw materials from which he will be able to build surer harmonies. Great names arise as we reflect upon the past—Rood Maxwell, Lambert, Mile, Clerk-Maxwell, Young, Helmholtz, Brewster, Chevreul. Some sure of their place, others passing with the passage of time and the sureness of modern investigation. Until we come at last to Dr. Wilhelm Ostwald, of Leipsic, whose work Colour Science has engendered new interest and a tremendously active period of experiment and reassess ment of colour values and colour classification and colour measurement. Dr. Wilhelm was born in 1853 and died in 1932. He was a man full of honours, for the Universities had recognized his greatness and in 1909 he received the Nobel Prize. The Ostwald System has been known among serious students of colour for quite a long time, but it was per haps not until J. Scott Taylor, M.A., translated Colour Science that England grew alive to this latest develop ment within the world of colour. 21b The educational world in this country has been quick to seize upon the Ostwald Theory for the very purity of its colours has brought more life and more creative effort into the art room and the class-room since the onslaught of Thring than perhaps any other pro nouncement. What, then, is the Ostwald Theory that it should cap ture so quickly the imagination of our educators and so enter the field of the professional artist and designer? If I were to be asked to reply to that question in one wordas I have been asked to do soI would say, as I then said, Simplicity. It is the rational, the logical, the common sense basis of the theory that constitutes its strength. Ostwald has charted the coloured worldthe world of colours. His basis is easy to understand. If you will look at my chart you will see the whole analysis there. The eye is the organ of vision. Colour is a sensation. Light enters the eye and sets up a sensation by its interplay upon the retina of the eye, for when the rays of light fall upon the retina, a sensory impulse results and this is conveyed to the brain by the optic nervethereby creating a sensation. The recognition of colour follows the same process and this must, of necessity, include the recognition of black as a colour. For although to say so to a physicist is to invite disaster, black gives a negative sensation and must therefore take its place among the colours. Sir William Bragg, in one of his excellent broadcasts upon Colour and Vision, indicated that there were three stages in colour recognition. The first when the eye is attracted by a colour. This attraction was due to the physical properties of a coloured surface. The second when the retina receives the sensory impulse and conveys the impression to the brain. Such a con veyance implies the physiological properties of the human organism. And, thirdly, when the brain receives the "message" and translates it. The translation implying the psychological properties of the mind and its relationship to its surroundings. So to revert to my chart. See page 219.) The eye is the basis of vision and dominates the whole

Industrial Arts en | 1936 | | page 58