[PDF] Researches On Colour Blindness With A Supplement On The Danger Attending The Present System Of Railway And Marine Coloured Signals eBook

Author : George 1818-1859 Wilson
Publisher : Legare Street Press
Page : 208 pages
File Size : 38,61 MB
Release : 2021-09-10
Category :
ISBN : 9781015359581

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This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. To ensure a quality reading experience, this work has been proofread and republished using a format that seamlessly blends the original graphical elements with text in an easy-to-read typeface. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Author : George Wilson
Publisher : Theclassics.Us
Page : 88 pages
File Size : 16,38 MB
Release : 2013-09
Category :
ISBN : 9781230348063

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1855 edition. Excerpt: ... in this section, and the confusion of red petals with green leaves, to which the author has referred, as proving the obscurity of red to Mr Troughton's eyes, is so nearly universal among the colour-blind, that I may. thus far adduce Sir David as at one with me in regarding red as appearing dark or darkish when seen by them. He holds, however, also, it will be seen, the remarkable opinion that the red light of the spectrum may appear much brighter, instead of much darker, to a colour-blind eye than to a normal one, in consequence of the former not perceiving the red, but instead thereof, yellow light of the same refrangibility, which makes a much stronger impression upon the retina. Additional observations can alone determine whether the anticipated phenomenon ever occurs. Its occurrence, however, would not be at variance with the appearance of red or crimson bodies as black to a colour-blind eye, as they do not transmit or reflect yellow rays to affect the retina. It is otherwise with scarlet bodies, which should appear as bright yellow to eyes which simply ignored red. But it is with green, not with yellow, that scarlet is systematically confounded by the colour-blind, as a review of all the recorded cases will fully demonstrate, and the green thus identified with scarlet is not a pale or yellowish green, but a full, and often dark, shade of that colour. Thus, Dalton compared sealing wax to one side of a laurel leaf, and a red wafer to the other, and his doctor's scarlet gown to the leaves of trees; nor was his case in this respect peculiar, for the colourblind are constantly found unable to distinguish the petals of the scarlet geranium from its leaves, the flowers of the wild poppy from the unripe corn amongst which it is growing, and...

Author : George Wilson
Publisher :
Page : 214 pages
File Size : 45,65 MB
Release : 2020-05-11
Category :
ISBN : 9780461932386

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This is a reproduction of the original artefact. Generally these books are created from careful scans of the original. This allows us to preserve the book accurately and present it in the way the author intended. Since the original versions are generally quite old, there may occasionally be certain imperfections within these reproductions. We're happy to make these classics available again for future generations to enjoy!

Author : B. Drum
Publisher : Springer Science & Business Media
Page : 424 pages
File Size : 18,90 MB
Release : 2012-12-06
Category : Medical
ISBN : 9401118566

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The eleventh Symposium of the International Research Group on Colour Vision Deficiencies (IRGCVD) was held 20-23 June 1991 in Sydney, Aus tralia, ably hosted by local organizer Stephen Dain. A total of 35 talks and 10 posters were presented. Papers based on 37 of these presentations are included here, in Colour Vision Deficiencies XI. The scientific program featured sessions on three special topics, with each topic highlighted by an invited speaker. The opening session on the Genetics of congenital colour vision deficiencies began with a superb invited lecture by Charles Weitz about his pioneering work on the molecular genetics of tritanopia. The session on the second special topic, Spatial aspects of colour vision, began with the launching of a new IRGCVD tradition, as 1991 Verriest Memorial Award recipient Harry Sperling presented the first Ver riest Memorial Lecture on his recent studies of spatial discrimination of heterochromatic stimuli. Dr. Sperling reported new evidence that certain asymmetries in red-green opponent colour vision can be explained by the spatial organization of colour-opponent retinal neurons. In the third special session, on Occupational aspects of colour vision, Barry Cole took the audi ence on a fascinating tour of the historical development of colour vision standards in his invited lecture entitled 'Does defective colour vision really matter?'. In addition to the three special topics, many interesting presentations were given in topical sessions on Variations in normal colour vision, Acquired colour vision deficiencies and Colour vision tests and testing methods.