POINTILLISM, the division of tones in painting by very small dots of equal size, caus ing the spherical shape to act equally upon the retina of the beholder's eye. The accumulation of these luminous points is carried out over the entire surface of the canvas. The theory of complementary colors is systematically applied (see IMPRESSIONISM). Pointillism is an off shoot of impressionism, a movement that coin cided with certain scientific research concerning optics: Helmholtz had published his works on the perception of colors and sounds by means of waves; Chevreul had established his beauti ful theories on the analysis of the solar spec trum; and Charles Heary, an original thinker, had applied these new principles to aesthetics and had the idea of establishing relations be tween optics and the laws of painting. These researches found fruit in the work of the younger painters of the impressionist school, who thought of carrying its chromatic prin ciples still further. These painters, working from about 1880 to 1889, endeavored to establish some laws concerning the reaction of tones and particularly those concerning complemen tary colors — in such a manner as to be able to draw up a kind of table or system.
Georges Seurat and Paul Signac were the pro moters of this research; and to these two paint ers is due the method of Pointillism. The works of Seurat, Signac and other artists who have strictly followed the rules of Pointillism are somewhat lacking in life, spontaneity, caprice and charm; for the dryness and mathematical quality of the style (which reduces a picture to a kind of theorem excluding all that gives charm to a work of art) afford scant opportu nity for the display of individual temperament. Besides Seurat and Signac other Frenchpaint ers of this so-called Neo-Impressionist School are Maurice Denis, Henri Edmund Cross, An grand and Camille Pissaro (1831-1903). The Belgian, Theo Van Rysselberghe, is also an exponent of the Pointillist method. There are also a number of painters in the United States who work in this style. The Neo-Impression ists, like the Impressionists, are chiefly occupied with the problems of light, following the in struction laid down by Manet: °The principal person in a picture is the light.°