Essays and observations on natural history, anatomy, physiology, psychology, and geology / by John Hunter, being his posthumous papers on those subjects, arranged and revised, with notes ; to which are added the introductory lectures on the Hunterian collection of fossil remains delivered in the theatre of the Royal College of Surgeons of England, March 8th, 10th and 12th, 1855 / by Richard Owen.
- John Hunter
- Date:
- 1861
Licence: Public Domain Mark
Credit: Essays and observations on natural history, anatomy, physiology, psychology, and geology / by John Hunter, being his posthumous papers on those subjects, arranged and revised, with notes ; to which are added the introductory lectures on the Hunterian collection of fossil remains delivered in the theatre of the Royal College of Surgeons of England, March 8th, 10th and 12th, 1855 / by Richard Owen. Source: Wellcome Collection.
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![materials which are flexible. Their strength has to be equal to the accidental force applied, tending to dislocate the parts which they unite. Most of our muscles, with their tendons, become, indeed, principally the ligaments in the motions of the joint, arising from their own action. But every joint is not sufficiently surrounded with muscles and tendons to guard it in eveiy direction; therefore it must have ligaments as a substi- tute. The thigh-bone at the union with the pelvis, and the humerus at the union with the scapula, are so surrounded with muscles that it is hardly necessary for them to have ligaments, excepting to retain the synovia. However, as those large joints are subject to various motions, not pro- duced by their muscles, it was necessary they should have ligaments of some strength; although these are not always equal to the force of such motions, which are commonly called accidental. The ligaments of joints are inserted at a distance from the moving point, in a proportion equal to the quantity of motion, which motion is always from the received bone, viz. the thigh-bone and the humerus. It is equally so in the ginglymus and conoid joints; for, in the ginglymus, the ligament is inserted at a great distance from the point of motion on the flexing and extending sides, but is much nearer to the lateral, and in the true conoid the ligaments are inserted at equal distances all round. The vertebras of the quadruped are never, in any action of the animal, in danger of being pulled asunder, but they are liable to be broken asunder; therefore the union of the two is such as is a hindrance to their being broken, the strong part of the union being exterior, and the weak one in the centre. The simple motion in every joint is the sliding one; but from the difference in the articulations, and the different directions of the bones, different effects are produced, which have given rise to different classes of joints, and of course to different names for them1. [Practical Anatomy.] Of the Arrangement of Anatomical Preparations. Parts of animals are often so combined, in their connexions and uses, as to make it impossible to separate them so as to make a series of anatomical preparations, perfectly classed according to their uses only; the vesica urinaria, e. g., is connected entirely with the kidneys, as to use; but is so connected with the penis, &c. as to situation, as to make them inseparable. The urethra belongs equally to both. 1 [The work had not proceeded beyond the second chapter. The following is a supplemental one on practical anatomy, or the art of making and arranging anatomical preparations.]](https://iiif.wellcomecollection.org/image/b21182656_0410.jp2/full/800%2C/0/default.jpg)
