PHYSIOLOGY OF COLOR VISION 451 



At the present day there is an unrest in the world of art, an unrest 

 which has resulted in the creation of innumerable schools, each endeavor- 

 ing by some peculiar method of its own to inculcate new principles and 

 to establish new ideals. Within a short period of time realism has 

 given place to impressionism, impressionism to post-impressionism, and 

 this again has become parent for so many other "-isms," that, to follow 

 them, has become almost impossible. However unpictorial from our 

 ordinary viewpoint the creations of some present-day artists may ap- 

 pear to be, there is nevertheless in many of them some newly discovered 

 truth; they are the steps in an evolution, and we may hope that some 

 day the evolution will be consummated and that from out of the 

 apparent chaos, which at present exists, a really compelling picture will 

 be created. 



It is most of all in landscape painting that the evolution of modern 

 art can be seen. The old landscapes of Claude Lorrain and Constable 

 are no doubt full of charm, but they entirely lack the atmosphere and 

 force of the so-called impressionist paintings of Monet, Sisley, Pissaro, 

 etc. In the older landscapes an attempt was made to copy everything 

 that could be seen by prolonged study, and the canvas was covered with 

 detail to its very edges; in impressionism, it is merely the flash, the 

 fleeting effect of the landscape which it is attempted to reproduce. 

 There may indeed be considerable detail in certain portions of the 

 picture, but the greater part is merely a color pattern. But after all 

 such an impressionistic picture can occupy our attention for a moment 

 only. "We do indeed receive an impression more or less like that which 

 the artist received on viewing his object, but closer study of the picture 

 does not carry us farther; there is something absent from it with which 

 nature abounds, something that compels us, as when viewing a land- 

 scape, to keep shifting our gaze from point to point, a restlessness, a 

 constant source of interest and fascination. In post-impressionism the 

 attempt is being made to supply this want, to compel us namely to 

 regard more than the fleeting impression. The closer we study such a 

 picture, if it be successful, the more comes out of it, colors by their 

 influence on one another become changed in hue and saturation, a 

 curiosity develops and, subconsciously, we are compelled to continue our 

 study with the result that we get ever other and other effects. It is 

 kinetic, not static, art ; it is a pattern of nature designed to create visuo- 

 psychic impressions expressing an idea rather than an object, subjective 

 rather than objective. 



There is a physiological reason for this visual restlessness and before 

 we go into the science of colors it may be well to explain what this 

 reason is. The innermost layer of the eye, on to which images of 

 exterior objects are focused, is specialized to react to sensation of light, 

 thus setting up nerve impulses which are transmitted to the brain where 

 they are interpreted. This layer of the eye is called the retina and it i3 



