. Color-vision and color blindness, a practical manual for railroad surgeons . ed and green elements;hence the sensation of violet. When tlie elementssensitive to red, green, and violet are excited simulta-neously to the same degree, the resulting sensation iswhite. A glance at Fig. 11 shows that no color of thespectrum is fully saturated, for the reason that it alwayscontains more or less of the other two primary and blue are the most luminous colors of the COLOR-PERCEPTION AND COLOR-BLINDNESS. 31 spectrum, because the elements of two of the primarycolors are excited to a high d
. Color-vision and color blindness, a practical manual for railroad surgeons . ed and green elements;hence the sensation of violet. When tlie elementssensitive to red, green, and violet are excited simulta-neously to the same degree, the resulting sensation iswhite. A glance at Fig. 11 shows that no color of thespectrum is fully saturated, for the reason that it alwayscontains more or less of the other two primary and blue are the most luminous colors of the COLOR-PERCEPTION AND COLOR-BLINDNESS. 31 spectrum, because the elements of two of the primarycolors are excited to a high degree, while the elementssensitive to the other are excited to a considerabledegree. RED-BLINDNESS. According to the Young-Helmholtz tlieory blindnessto red is due to the absence or paralysis of the organsperceiving red (Fig. 12). Red-blindness has, then, buttwo fundamental colors,—green and violet. Accordingto Helmholtz, spectral red, w liich feebly excites theperceptive organs of green and scarcely at all those ofviolet, must consequently appear to the red-blind a satu-. rated green of a feeble intensity, more saturated thannormal green, into which a sensible portion of the otherprimitive colors enters. Feebly-luminous red, whichaffects the perceptive organs of red in a normal eye suf-ficiently, does not, on the other hand, sufficiently excitethe perceptive organs of green in the red-blind, and it,therefore, seems to them black. Spectral yellow seemsto them a green saturated and intensely luminous, and,as it constitutes the precisely saturated and very intenseshade of that color, it can be understood how the red-blind select the name of that color and call all thosetints that are properly speaking green, yellow\ Greenshows, as compared with the preceding colors, a more 32 COLOR-VISION AND COLOR-BLINDNESS. sensible addition of the other primitive colors; it thenappears, consequently, like a more intense but whitishshade of the same color as yellow and red. The greatestintens
Size: 2975px × 840px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1900, bookdecade1920, booksubjecteye, bookyear1920
