A treatise on the blood, inflammation, and gun-shot wounds / by John Hunter ; with notes by James F. Palmer.

  • John Hunter
Date:
1840
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the blood, inflammation, and gun-shot wounds / by John Hunter ; with notes by James F. Palmer. 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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    The common action of a muscle, from which its immediate use is derived, is its contraction; and the eilect produced by it is that of bringing the origin and insertion, or the parts which it is fitted to move, nearer to each other;* which is universally the case whether the muscle is straight, hollow, or circular. It is likewise necessary that a muscle should relax, or be capable of relaxation ; a condition which allows it to be stretched, by permitting the parts acted upon to recede from each other. Muscles, in common, probably, with every other part of the body, have a power of adapting themselves to the necessary distance between origin and insertion, in case an alteration has taken place in the natural distance ; and I have reason to believe that, under certain circumstances, they have a power of becoming longer, almost immediately, than they are in the natural relaxed, or even the natural elongated state of their fibres. This opinion will be best illustrated in inflammation. Muscular contraction has been generally supposed to arise from some impression, which is commonly called a stimulus; I doubt, however, of an impression being always necessary ; and I believe that in many cases the cessation of an accustomed impulse may be- come the cause of contraction in a muscle. The sphincter iridis of the eye contracts when there is too much light, but the radii contract when there is little or no light.f I can even conceive that a cessation of action requires its stimulus to produce it, which may be called the stimulus of cessation ; for relaxation is not the state into which a muscle will naturally fall upon the removal of a continued stimulus ; a muscle remaining contracted after absolute death, when the stimulus of relaxation cannot be applied ; so that a muscle can as little relax after death as it can contract.J If a stone is raised, and the raising power removed, it falls ; but it would not fall if not acted upon. When it has fallen it lies at rest; but so it would have done when raised, if gravitation would have allowed it. The stone is passive, and must be acted upon. Whatever * I do not here consider the circumflex tendons ; for, by the origin and in- sertion, I mean the muscular ends of the fibres. f [Dr. Parry objects to this illustration, and thinks that the radii of the irisre- store themselves by their simple, tonicity, in the same manner as other muscles. It may be observed, that the fact of the muscularity of the iris, which is here presumed from analogy by Mr. Hunter, has been since directly proved by the observations of Bauer and Jacob {Phil. Trans. 1822), and indirectly by Ber- zelius, who found that the iris possesses all the chemical properties of muscle. Dr. Roget also has informed us that the iris of his eye is partly under the influ- ence of the will; and Mr. Mayo, that in some animals it instantaneously con- tracts on any mechanical irritation of the third pair of nerves {pp. cit., p. 291); phenomena which are obviously only referrible to a muscular structure.] X [Muscles which have long been contracted lose all disposition to rehix, as may be observed in Fakirs and other religious visionaries, who compel them- selves to remain in constrained positions of the body for a Ion? time together, and in the contractions which follow diseases of the joints. Even a powerful grasp of the hand, continued only for a few minutes, is recovered from with difficulty. That peculiar tetanic spasm of the lower extremities which is in- duced by injecting a solution of opium into the stomach of a frog, is not relaxed by a division of the spinal marrow above the origin of the lumbar nerves.]