Observations on vision : ... Read before the Royal Society of London, May 1, 1794, and published in their Transactions of the same year. Communicated to the Society by George Pearson.

  • Hosack, David, 1769-1835.
Date:
1813
Catalogue details

Licence: Public Domain Mark

Credit: Observations on vision : ... Read before the Royal Society of London, May 1, 1794, and published in their Transactions of the same year. Communicated to the Society by George Pearson. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    Of the structure of these processes Haller observes, In omni certe animalium genere processus ciliares absque ulla musculosa sunt fabrica, mere vasculosi vasculis serpentinis percursi molli facti membrana ; which structure, I believe, at present is universally admitted. But even supposing them muscular, such is their delicacy of structure, their attach- ment, and direction, that we cannot possibly conceive them adequate to the effects ascribed to them. Besides, what we observed of the muscles of the lens itself, also applies to the processes, viz. that they may be destroyed, as in couching or extraction, and yet the eye be capable of adapting itself to the different distances of objects. For a more full refuta- tion of these opinions, see Haller's large work. The Situation, Structure, and Action of the external Muscles.* Upon carefully removing the eyelids, with their muscles, we are presented with the muscles of the eye itself, which are six in number; four called recti, or straight; and two oblique; so named from their direction, (see plate Hd. fig. 1.) A A A A, the tendons of the recti muscles, where they are inserted into the sclerotic coat, at the anterior part of the eye. B, the superior oblique, or trochlearis, as some- times called, from its passing through the loop or pulley con- nected to the lower angle of the orbiter notch in the os fron- tis ; it passes under the superior rectus muscle, and back- wards to the posterior part of the eye, where it is inserted by a broad flat tendon into the sclerotic coat. C, the inferior oblique, arising tendinous from the edge of the orbiter pro- * For the accuracy of the representation I have annexed (see plate Hd.) I can vouch, having been at much pains in the dissection ; from which I had the paint- ing taken by a most accurate hand, Mr. S. Edwards, a gentleman well known for his abilities in the plates of that admirable work, the Flora Londinensis.