General therapeutics and materia medica: adapted for a medical text book (Volume 2).

  • Dunglison, Robley, 1798-1869.
Date:
1843
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Licence: Public Domain Mark

Credit: General therapeutics and materia medica: adapted for a medical text book (Volume 2). 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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    Sir Gilbert Blane also asserts, that no muscle, whether volun- tary or involuntary, can act unless its fibres are previously in such a state, that if divided they would shrink by their own re- siliency, leaving an interval between the cut extremities; and Dr. Paris—after citing the above remark of Sir Gilbert, observes: — It appears, that there are certain medicinal bodies, that have the power of affecting this state of tension, and when their effects contribute to its restoration, they are properly denominated to- nics. Yet this resiliency, described by Sir Gilbert, is not neces- sarily even a vital manifestation. It may be independent of the vital properties. It continues for some time after the total extinc- tion of life in all its functions; appears to be connected simply with the physical arrangement of the molecules; and is not affected, until the progress of decomposition has become sensible. Hence, it has been properly regarded, by Haller and others, as a vis mortua. (See the author's Human Physiology, 4th edit. i. 49, Philadelphia, 1841.) Flexibility, extensibility, and elasticity are variously modified, and combined in the different forms of animal matter, and they exist, to a greater or less extent, in every organ. Elasticity is only exerted under particular circumstances. The tissues, in which it is inherent, are so disposed through the body as to be kept in a state of extension by the mechanical circumstances of situation, but, as soon as these circumstances are modified, elas- ticity comes into play, and produces shrinking of the substance. The gaping wound, produced by a cut across a cooked shoulder of mutton, is an example of this elasticity or resiliency, familiar to all. Previous to the division, the force of elasticity was kept neutralized by the mechanical circumstances of situation—or, by the continuity of the parts; but, as soon as this continuity was disturbed, or, in other words, as soon as the mechanical circum- stances were altered, the force of elasticity was exerted, and produced recession of the edges. This property of elasticity has been called contract ilite de tissu, and also tone or tonicity;— names, which have probably suggested the modus operandi assigned to tonics, which we have been discussing. That diminished cohesion, like that adverted to, may occur as the result of disease, is doubtless. Pathology affords us nume- rous examples of it, although not so many as is usually supposed; and it is by no means easy to see, that such a pathological condi- tion must always exist, when tonics are indicated, or whenever they prove beneficial. The only way, it would seem, that these agents can act on the muscles, is on their contractility, like exci- tants, and indirectly on their nutrition, through the medium of the nerves distributed to the stomach;—the irradiations being conveyed from thence to every part of the nervous system, and, therefore, to every portion of the frame endowed with nervous influence.