Color images in the brain : being an account of the detection of visible objects, seen posited on exchanged sides in the brain, after the intromission of impressions of light, reflected from external objects, one in each eye ... / by John Fearn.

  • Fearn, John, 1768-1837.
Date:
[1831]
Catalogue details

Licence: Public Domain Mark

Credit: Color images in the brain : being an account of the detection of visible objects, seen posited on exchanged sides in the brain, after the intromission of impressions of light, reflected from external objects, one in each eye ... / by John Fearn. 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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    principle in question the Principle of Co-incident linages:' Accordingly, in the close of the paper presented to the Royal Society, I have repeated what was said in the Ratio- nale ; where I expressed it as being the result of the whole continued series of proofs, first and last; and which the Abstract has quoted, correctly indeed, but as a mere suppo- sition which it appears to estimate light as air—namely that — Over and above the gift of two external or cranial eyes, man has been by his Adorable Creator endowed with an internal cerebral organ, which performs the office of a Third Eye, by being the common recipient of impressions propagated, either from one, or both of the external eyes; and that the mind, in her chamber of percipience, steers with regard to external objects, by the same principle on which the Mariner steers by his Compass. Thus, the two cranial eyes are analogous, in principle, and situation, to two Magnetic Compasses placed upon a ship's deck ; while the third, or Cerebral Eye, corresponds to another compass placed in the cabin below: And the mind, si- ** tuated like the captain mariner in his cabin, knows, from consulting the Cerebral Eye, upon what point of direc- tion the body is steering; although the Mind no more perceives either any external object, or yet any image in ** the cranial eye, than the mariner perceives, (even in the vulgar sense of the word perceiving) the far-off land, or *' haven, towards which he is surelv making his wav. Upon this result, I now offer the following gloss : though I think it is already indicated in the Rationale.—Every Spectator of a scene must allow—{a7id nature has well taught him how to do so)—for the VARIATION OF HIS Eye, as the mariner allows for the Variation of his Com- pass. Thus, if a man know that his head is twisted far to the right, and his eye twisted far to the right in his head; he then knows that the object he sees is nearly behind him: And this he does on the very same principle that the ma- riner, when he is steering North by his compass; and knows that his Compass has Ttvo Points of West Varia-