LONDON.- Every month during the Gallery’s bicentenary celebration year a spectacular masterpiece will hang on the end wall of the Gallery’s enfilade. Van Gogh painted this self-portrait in Paris, in the winter of 1887-1888. It reflects that city’s infl uence in its adaption of Pointillism, the use of small dots of pure colour to create an optical illusion of light. The technique had been quite recently developed by Georges Seurat in 1886. However, Van Gogh was never a slavish follower of other peoples’ theories, though a passionate developer of his own. While clearly interested in the colouristic effects that Pointillism enabled, Van Gogh liked his colours to shine to their maximum intensity – he uses not dots, but slabs of colour, and lays them out with a sense of direction to increase the sense of three dimensions. But, more than that,