Theory of colours and vision. / By G. Palmer.

  • George Palmer
Date:
MDCCLXXVII. [1777]
Catalogue details

Licence: Public Domain Mark

Credit: Theory of colours and vision. / By G. Palmer. Source: Wellcome Collection.

    40/48 page 38
    / [ 33 ] If it be fo, when Ifet one of thefeglaffes upon a fheet of paper, and look over it, it ought to appear of a colour quite different from what it does when I look through it: neverthelefs it appears of the fame colour, though a great deal darker. PALMER. According to authors who have written on the fubjedt, it ought to be fo; for many of them have faid, a red glafs tranjrnits the red ray, and reflects the blue and the yellow ones ; from which it fhould follow, that a red glafs fhould look green; a blue one, aurora; a yellow one, purple, &c. notwithflanding which it never does fo. But, according to my opinion, it abforbs and dejiroys ores ray, and tranfmits two. Upon which account, when you look through it, you have a ray of ftrong light, coloured by the want of the abforbed ray. When you look over it, then you receive but very little remedied light, becaufe it is a tranfparent body: and this light, even wanting the deftroyed ray, gives a very dark fenfation of this colour. If you fet this glafs upon a white body, the fenfation will be ftronger; many of the tranf- mitted rays being refledted by the white furface, and returned to the eye through the ghfs. The
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