Presidential address on the energy of the animal body / by W.F. Cleveland.

  • Cleveland, William Frederick, 1823-1898.
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: Presidential address on the energy of the animal body / by W.F. Cleveland. 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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    This is a startling assertion, and the explanation of it that would probably occur to most minds is that it is due to the sudden oxidation of carbonaceous substances in the muscle. Not so, however, for it is found by experiment that the in- creased production of carbonic acid during rigor mortis is not accompanied by a corresponding increase in the consumption of oxygen. The muscle of a frog placed in an atmosphere of pure nitrogen will not only give off carbonic acid while it is alive, but will also give it off at the onset of rigor mortis, showing conclusively that, as there is no oxygen present, the carbonic acid cannot be due to the direct oxidation of the muscle substance. The explanation of the phenomenon suggested is that during rigor mortis some complex body—which, by-tlie-bye, has never been isolated or its existence definitely proved— containing in itself ready-formed carbonic acid, is split up and the carbonic acid set free, but that the process of oxida- tion, which led to its formation in the muscle, took place at some anterior date. That the complex body which gives rise to the myosin clot, etc., of rigor mortis is the same stuff that gives rise to the carbonic acid, lactic acid, etc., of a muscular contraction seems beyond dispute; but the difference between them is this : In the living muscle the nitrogenous product of the contraction, unlike the solid myosin, is a soluble proteid, and, as it still contains energy, may in some way be utilised in the economy when the contraction is over. The theory, then, that is generally held at the present day—that of Hermann in regard to muscular contraction—is not that which was formerly taught, namely, that some nitrogenous portion of the muscular tissue underwent disintegration, and by so doing set at liberty the energy which up to that time had been potentially employed in holding together the com- ponents of the structure, but that it is effected through the chemical change involved in the splitting up or explosive decomposition of some complex body specially prepared for it, composed of carbon compounds, and that this body is lodged, so to speak, in the interstices of the living framework of the muscle. This is the contractile material that forms the newborn child’s capital of potential energy before alluded to—the muscle dynamite, or “inogen,” as it is sometimes termed. It is through the chemical combination of oxygen—oxygen conveyed by arterial blood and stored up in some mysterious way by the muscular substance within itself—with the inogen or carbonaceous constituent of the muscle that oxidation or explosive decomposition is effected. In other words, the living gun is fired off, the result being contraction of the muscle, evolution of heat, and the setting free of carbonic acid as an oxidation product. As that form of energy—or mode of motion, as it has been called by Professor Tyndall—which initiates the oxidation of wood or coal and sets it burning is heat, so that form of energy which starts the oxidation of muscle substance and brings about a muscular contraction is, broadly speaking, nervous impulse ; but the steps that are taken by the oxygen, from the time that it leaves the blood to the time it issues from the system as carbonic acid are wrapt in obscurity. But we may inquire from whence the carbo-hydrates, that have so much to do with the potential energy of muscle, are derived. In the first place, fats, which have a varied chemical compo-