Colour-blindness: With a Comparison of Different Methods of Testing Colour-blindnessK. Paul, Trench, Trubner & Company, Limited, 1925 - 237 pages |
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Common terms and phrases
anomalous trichromates appears Black+White blue and violet blue and yellow Blue Blue Blue blue-green bluish pink bright brown green called cards colour naming colour sensations colour theories colour vision colour-vision confusion confusion confusion crimson dark green dark grey dark red dichromic disc distinguish Dr Collins fact fovea George Combe glass green and red green blue green brown Green Green Green Green Yellow green-blind Grey Grey Grey Helmholtz Helmholtz theory Holmgren light Brown light Grey magenta matched neutral band normal eye orange pale blue pale green protanopia Psychology pure green recognized red and green red and violet red end Red Red Red red-blind red-green blindness red-green colour-blindness reddish green retina rods scotoma seems seen shades of grey shortened spectrum Stilling's Tables stimulation substance test skeins totally colour-blind violet end visual purple W. H. R. RIVERS wool test yellow and blue yellow-green yellowish Young-Helmholtz theory
Popular passages
Page 4 - I accidentally observed the colour of the flower of the Geranium zonale by candlelight in the autumn of 1792. The flower was pink, but it appeared to me almost an exact sky-blue by day ; in candlelight, however, it was astonishingly changed, not having then any blue in it, but being what I called red — a colour which forms a striking contrast to blue.
Page 73 - ... large number at the same time, to instruct all at once, and, moreover, to ask them to attentively observe the examination of those preceding them, so as to become more familiar themselves with the process. By this, time is saved, without loss of security; for no one with a defective chromatic sense finds the correct skeins in the pile the more easily from the fact of having a moment before seen others looking for and arranging them. He makes the same characteristic mistakes; but the normal observer,...
Page 57 - ... but there is a defect in the perception of colour. In the first class certain rays are either not perceived at all or very imperfectly. Both these classes are represented by analogous conditions in the perception of sounds. The first class of the colour-blind is represented by those who are unable to hear very high or very low notes.
Page 28 - He appeared delighted to renew his acquaintance with this colour, and he declared that he had not seen it for several years. The glass was then held near the light, while he went to a distance ; but in this case no colour was manifest ; neither was any colour seen when a gas-lamp was regarded through the same glass. The intense action due to proximity to the electric light appeared to produce the effect.
Page 6 - Though I see different shades in looking at a rainbow, I should say it was a mixture of yellow and blue, — yellow in the centre, and blue towards the edges.
Page 3 - Having by accident found in the street a child's stocking, he carried it to a neighboring house to inquire for the owner. He observed the people called it a red stocking, though he did not understand why they gave it that denomination, as he himself thought it completely described by being called a stocking.
Page 53 - The character of the stimulus and impulse differs according to the wave-length of the light causing it. In the impulse itself we have the physiological basis of the sensation of light, and in the quality of the impulse the physiological basis of the sensation of color.
Page 75 - The names of colors are naturally the objective expression of subjective sensations ; but, on the other hand, they are regulated by the system of normal sight, and cannot, consequently, agree with that of the colorblind.
Page 8 - ... identical with that produced by causing the light of the different colours to fall on the retina at once. By properly arranging the discs, any given colour may be imitated and afterwards registered by the graduation on the rim of the top. The principal use of the top is to obtain colourequations. These are got by producing, by two different combinations of colours, the same mixed tint. For this purpose there is another set of discs, half the diameter of the others, which lie above them, and by...