Daltonism.

  • Pole, William, 1814-1900.
Date:
[1880]
Catalogue details

Licence: Public Domain Mark

Credit: Daltonism. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    DALTONISM. : /f?o THIS is the name given, in many parts of Europe, to a curious defect in the vision of colours, -which was first prominently brought into notice by the immortal discoverer of the Atomic Theory, in a description written by him of his own case. English authors use in preference the term Colour-blindnessasserting that the conti- nental designation is disrespectful to a great man; but there appears reason to believe that the word was used in Dalton's lifetime, and gave no offence to him. Indeed he was more amused than annoyed by his singularity of vision, and was always ready to satisfy the curiosity of others in reference to it. I use the personal name here, as I shall have much to say about the phenomena of Dalton's vision. The subject has lately been attracting much notice ; it is a matter of curiosity to the public, and of physiological interest to scientific men; and moreover it has some practical bearings. It is, however, still imperfectly under- stood, and many points connected with it are open to controversy. I propose, as a humble successor of Dalton in the experience of the defect, to give some account of the most modern state of knowledge in regard thereto. The perception of colour would seem, according to the ideas of those who have not studied the subject, to be as positive and unmistakable as the perception of form. Take, for example, a square red flag: the world in general will consider the redness of the flag to be a quality about which there can be as little mistake as its squareness, and they can no more understand how anyone can see it' as green or yellow, than how he can sec it as round or triangular. I have often amused myself by watching the odd impression produced on intelligent shop- assistants who have to do with colours, by a mention of some of the peculiarities of colour-blindness. Taking up, say, two ribbons of