Manual of gynecology / by D. Berry Hart and A.H. Freeland Barbour.

  • Hart, D. Berry (David Berry), 1851-1920.
Date:
1905
Catalogue details

Licence: Public Domain Mark

Credit: Manual of gynecology / by D. Berry Hart and A.H. Freeland Barbour. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    These terms are scientifically misleading as the great resistance tends to counteract the high electro-motive power, and the principal phenomena of electro-magnetism are due not to the mere presence of electricity, however great in its tension, but to its state of current or flow. The terms are, however, convenient; and, what is more to the purpose here, Apostolus whole method is founded upon his declared discovery that the physiological effects of currents in the two conditions are very different. ACTION OP DIFFERENT CURRENTS AND POLES. Action of the Galvanic or Continuous Current. The mode of action of a continuous current is different at the two poles. It is thus lucidly described by Milne Murray. This will be best understood if we study, in the first place, the effect of the passage of the current through a piece of dead tissue—say a piece of beef. A small block of fresh beef is placed on a dish, and into it two steel sewing needles are inserted at a distance of an inch from each other. One of these is connected to the positive and the other to a negative pole of a battery, and a current of, say, 50 m.a. is transmitted. The following things will be observed. 1st. In a few seconds a frothy effervescence will appear round the negative needle, while the tissue will shrink and condense round the positive needle. 2nd. If, at the end of a few minutes, the negative needle be gently pulled, it will come away without difficulty, leaving an aperture a good deal wider than its own thickness; this aperture opens into a sinus which is filled with a soft frothy scum. 3. If the positive needle be similarly pulled, it will not come away without considerable traction, and will leave a small orifice with a dense firm outline. 4th. On examination, the negative needle will be found quite bright while the positive needle will be dulled and slightly corroded. 5th. If the piece of meat be now carefully cut open, so as to expose the channels formed by the needles, it will be found that the tract of the negative needle is surrounded by a softened loose area of disorganised tissue, while the tract of the positive is surrounded by a condensed area much smaller than that round the negative needle ; it is, moreover, paler in colour, and cuts with a somewhat gritty sensation. 6th. If the surfaces so exposed are tested with litmus paper, it will be found that on the negative side an alkaline and on the positive side an acid reaction is given. In addition to the action at the poles, Apostoli and others have affirmed that there is an interpolar action through the entire uterine substance. Of this there is no evidence. Thus Milne Murray says, Any so-called experimental proof which has been advanced in favour of the existence of interpolar decomposition can be readily explained on other grounds; and we may take it that there is no proof of any elec- trolytic action occurring anywhere except round the metallic electrodes.