COLOK-BLINDNESS. 175 COLOR PHOTOGRAPHY. This road, in June, 1901, employed about 40,000 men, and controlled 7137.31 miles of track, in- clusive of the leased lines, such as the Xew York and Putnam ; West Shore ; Fall Brook : Boston and Albany, etc.; but e.xclusive of the great lines, such as the Lake Shore and Michigan Southern, included in the 'V'anderliilt system.' Consult: Holmgren, De la- cccilc dcs coiileurs (Sweden, 1877); Joy .Jeffries, Color-BUndness (Boston, 1879); Swanzy, Diseases of the Eye, appendix i. (Philadelphia. 189G) ; and Thomson and Weiland, "Detection of Color-Blindness," in Jlori'is and Oliver's Si/stein of Diseases of the E!/e,o. ii. ( PhiUulclphia, 1897). COLORED HEARING, or Ciirom.esthesia. The anomalous association of colors with sounds. It is the commonest type of sj-noestliesia, or the formation of unusual connections between sen- sations of different sense departments. While colored hearing is relatively frequent (statis- tics record one person in eight ) , it is exhib- ited in veiy varied forms. These may, however, be grouped, in the first place with regard to the nature and intensity of tlie photism (the color which is induced), and secondly with re- gard to the nature of the inducing sound. The induced color may, in rare cases (see works of Orubcr and Whipple, indicated in the bibliog- raphy at the end of this article) , be of hallucina- tory intensity, so as to be seen objectively when the eyes are open. Usually the intensity is less — the photism is localized (Flournoy), though not projected. In the third grade the jdiotism is 'imagined' — the color is really pres- ent as a visual sensation, but has no definite place ; e.g. all soprano voices may be white, all tenor voices green. Fourthly, photisms may be simply "'thought,' no visual sensation being pres- ent. Finally, certain persons possess 'negative photisms' — they cannot say what color a sovmd has, but can say what colors it 'ought not' to have. Any auditory impression may serve as the inducing agency. The sources may, therefore, be grouped, for convenience, as ( 1 ) miisieal tones and noises (subdivided into single notes, chords and discords, musical selections, etc., each with further arrangement according to pitch, intensity, clang-tint of instrument), and (2) articulate speech (vowels, consonants, words, sentences ) . Can we find any uniform relation between these two series of variables, the inducing sound and the induced color? Certain investigators, using the questionary method, have answered in the affirmative. Thus, Bleuler and Lehmann that "sharply demarcated, small, bright, or pointed photisms are aroused by high-pitched sounds. Red, yellow, and brown are frequent colors; violet and green are rare; blue stands midway in frequency. The tendency to second- ary sensations ( synsesthesia ) is inheritable." Other investigators (e.g. Whipple), who have made detailed experimental studies of a few individuals, contend that the questionary method is inadequate, and that there is a considerable degree of variation, not only between individuals, but also for the same individual at different times, so that "generalization is at present to be avoided." The explanation of colored hearing is usually found in the persistence in adult life of certain curious and useless connections between sensa- tions. Childhood is characterized by the forma- tion of countless mental combinations. Of these, only the useful or meaningful normally sur- vive. The jiersistence or lecrudesccnce in the mature individual of anomalous though not ab- normal auditory-visual connections is the con- dition of chroma?sthesia. The association may be direct (habitual or specific connection of sensations) or indirect (connections of .sensa- tions through the organic complex embodied in a feeling). The absence of abnormality is at- tested by the facts that colored hearing is no more frequent among neurotic than among nor- mal individuals, and that the associations do not intcrfei'e with mental operations. They may, indeed, furnish positive sources of pleasure to their possessor. Consult: Bleuler and Lehmami, Zwanysmiis- sifie Lichtcmpfindiing (lurch tichall (Leipzig, 1881): Flournoy, hes phcnomviies de synopsie (Paris, 1893) : G. M. Whipple, American Jour- nal of I'syehology, vol. vi. (Worcester, 1900) ; C4ruber, L'audilion coloree et les pluiiomeiies similaires (Paris, 1892). COLORED METHODIST EPISCOPAL CHURCH OF AMERICA. See Methodism. COLOR-GUARD. A military escort for regimental colors. (See Colors.) Formerly a position of great honor and considerable dan- ger, when on active service: now used only on regimental parades, reviews, and inspections. The L'nited St-ates Infantry Drill Regulations define the composition of a color-guard as "one sergeant, who is the color-bearer, and two experi- enced soldiers, selected by the colonel." The color is kept at tiie oflice or quarters of tile colonel, unless required on parade, in which case it is escorted by the color-guard, marching in one rank, the color-bearer in the centre. It is returned in like manner. COLOR PHOTOGRAPHY. The reproduc- tion by photography of natural objects in their own colors. There is no means known at present by which, using ordinary photographic processes, this is possible. When a photograph is taken with a camera and a sensitive plate, the devel- oped negative shows an image of the object in various shades of gray, which depend u])on the sensitiveness of the photographic plate to the ether-waves characteristic of the colors of the natural object. It is possible so to stain a pho- tographic plate that it is more or less sensitive to all colors : but the developed negative is' always gray, except possibly for certain accidental colors which have not the faintest connection with those of the object photographed. To reproduce the colors, therefore, other methods are essen- tial, and there are at the present time two quite distinct processes. One of these is based upon the work and a suggestion of Prof. J. Clerk ilaxwell (1831-79), of the University of Cambridge. He showed that if there were produced sinniltaneously in the normal eye three sensations — viz. definite shades of blue, green, and red — the eye could be made to perceive any desired color of the spectrum by properly adjusting the intensities of these three component sensations. Thus, if by any means — e.g. by sets of mirrors — the eye can be made to see at one time three ordinary photographs of any natural object, looking at one through a piece of red glass, another through a piece of green glass, and the third through a piece of blue glass, the
