Red has also another peculiarity explanatory of the predilection shown for it by the hysterical. The experiments of Binet[42] have established that the impressions conveyed to the brain by the sensory nerves exercise an important influence on the species and strength of the excitation distributed by the brain to the motor nerves. Many sense-impressions operate enervatingly and inhibitively on the movements; others, on the contrary, make these more powerful, rapid and active; they are ‘dynamogenous,’ or ‘force-producing.’ As a feeling of pleasure is always connected with dynamogeny, or the production of force, every living thing, therefore, instinctively seeks for dynamogenous sense-impressions, and avoids enervating and inhibitive ones. Now, red is especially dynamogenous. ‘When,’ says Binet,[43] in a report of an experiment on a female hysterical subject who was paralyzed in one half of her body, ‘we place a dynamometer in the anæsthetically insensible right hand of Amélie Cle.... the pressure of the hand amounts to 12 kilogrammes. If at the same time she is made to look at a red disc, the number indicating the pressure in kilogrammes is at once doubled.’ Hence it is intelligible that hysterical painters revel in red, and that hysterical beholders take special pleasure in pictures operating dynamogenously, and producing feelings of pleasure. If red is dynamogenous, violet is conversely enervating and inhibitive.[44] It was not by accident that violet was chosen by many nations as the exclusive colour for mourning, and by us also for half-mourning. The sight of this colour has a depressing effect, and the unpleasant feeling awakened by it induces dejection in a sorrowfully-disposed mind. This suggests that painters suffering from hysteria and neurasthenia will be inclined to cover their pictures uniformly with the colour most in accordance with their condition of lassitude and exhaustion. Thus originate the violet pictures of Manet and his school, which spring from no actually observable aspect of nature, but from a subjective view due to the condition of the nerves. When the entire surface of walls in salons and art exhibitions of the day appears veiled in uniform half-mourning, this predilection for violet is simply an expression of the nervous debility of the painter.