Color-Blindness.

Manufacturer and builder 9, 1870

By the permission of the author, we take from a recent most sensible and most beautifully printed book, entitled, "How shall we Paint our House?" by Mr. John W. Masury, the head of one of our largest paint. manufacturing establishments, the following interesting article on the above subject:

"To say that one has 'no ear for music,' is a common and properly significant expression, and the want of it is considered not only a misfortune, but is frequently made a subject of reproach. Its absence is popularly supposed to indicate the presence of certain qualities which render a man unworthy the confidence of his fellows. To say that one has 'no eye for color,' is equally proper and significant; but as yet, among our own people, such a misfortune is not supposed to furnish good ground for impugning a man's sincerity, or to unfit him for the occupation of any position of trust or confidence. Yet it would bo difficult to give a plausible reason why 'his affections' should be 'dark as Erebus' in the one case, and not in the other.

"The faculty to discriminate color exists, in different individuals, in all the various degrees of development. The want of seneibility to colorimpresskne is generally supposed to be peculiar, and the affection in marked crsea is termed 'color-blindness;' but, in the opinion of the writer, it will be difficult, if not impossible, to draw the line to determine who are and who are not color-blind. Doctor Wilson, of Edinburgh, in 1853, published a work on color-blindness, wherein he an ranges the different forms or degrees of dullness to color-impressions, as manifested by different individuals.

"The first form, which is common among males, particularly of the educated classes, is shown in the inability to distinguish certain tones of browns from certain tones of green; say a dull green from a dingy brown; the second, an inability to distinguish certain primary colors, as rail front green; the third, an inability to distinguish any color, as such; the person affected in the latter degree seeing only white and black, lights and shades. In the first degree, this affection is, among males, perhaps the rule rather than the exception, and is owing, probably, to a lack of education in the discrimination of colors. In support of this hypothesis, the fact may be mentioned that deaf mutes possess this power of discrimination to a high degree. Being deprived of the use of those most important faculties, hearing and speech, the organs remaining to them are called into action to an extent quite impossible with those who possess all the faculties unimpaired. Hence such persons become, [-]sciously, highly educated in the discrimination of tones, hues, and shades.

"An instance illustrative of this fact fell under the observation of the writer, in the person of a deaf mute, a girl, the offspring of a married couple who were related to each other in the degree of first cousins. This child was of rare personal beauty, both of face and figure, and the senses remaining to her were quickened to a degree quite uncommon with children generally. In the room occupied by the writer was a large piece of Berlin worsted work, and a basket containing the remnants of the colored yarns, portions of which had been used in the production of the work. The child was a frequent visitor, and it was a source of great interest and amusenemt to observe how unerringly she would select from the basket the yarn corresponding to any designated hue on the work. No matter how slight the difference in shades, she never made a mistake in the selection. Dr. Wilson found that the majority of pupils in the chemical class at the veterinary college in Edinburgh declined to name any colors beyond red, blue, green, yellow, and brown; while they failed entirely in attempting to arrange nearly related hues of yarns, or those of varying shades of the same hue, and that pink and other pato colors, as pale yellow, blue, and green, were often confounded. In the second degree, in the less marked cases, red and green, and these with olive and brown, failed to be distinguished.

"It is by no means uncommon to find person* unable to distinguish the red fruit on an apple-tree from the green of its leaves. Three brothers are mentioned by Dr. Wilson who mistook red for green, orange for grass-green, yellow for light green. In the third degree, cases of which are rare, all colors are recognized only as giving certain degrees of light and shade. Instances are related of tailors, who matched black cloth with red thread, and scarlet livery with green strings; of a physician who never found a case of scarlet fever; of a gentleman who condoled with a lady supposing her in weeds, when she was dressed in a vivid green; of a Quaker who purchased a bottle• green coat for himself, and a scarlet merino gown for his wife; and of a schoolgirl who attempted to arrange the colors in her drawing by the sense of taste.

The causes of color-blindness are difficult to trace: it occurs equally with light and dark eyes, and is confined mostly to the educated classes, the female sex, however, furnishing but few examples. Among the savage tribes no case has ever been known.

"These instances of color-blindness are given, to meet the objection which will be made to the theory that color is a sensation, and not a substance. It must be borne in mind that, for all other practical purposes, the visual organs in those persons affected by color-blindness were as perfect as are those of ordinary individuals. The defect is somewhere between the eye and the brain; either the eye is incapable of transmitting the colored rays of light, or the brain is incapable of experiencing the sensation of color: arguing from general principles, we should say that the defect is in the optic nerve, and is simply a want of sensibility to certain impressions, bearing the tense relation to the waves of light use the hearing, in these persons who are said to have no ear for music, does to the waves of sound. It is well known that those who are insensible to musical sounds, who can not distinguish the tones in the musical scale, are for other purposes sufficiently acute in the sense of hearing; but be the cause what it may, there will be no difficulty in arriving at the conclusion that one as affected should not adopt the calling or profession of painting, or any other trade wherein a nice sense of discrimination between colors and shades is required."