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The electro-therapeutic guide, or, A thousand questions asked and answered . r the same reason that it begins in any one of the elements is partially prepared in advance by perforat-ing it with holes and filling the holes with oxide of lead. This kind of bat-tery may be used for cautery work, or for running such machinery as fansetc. It is heavy and not easily moved about. It is also an expensive kindof battery. This prepared element is called a grid. 36 THE ELECTRO-THERAPEUTIC GUIDE DENSITY AND DIFFUSIONWhat is ttnderstood by density and diffusion? Density and diffusion are ter
The electro-therapeutic guide, or, A thousand questions asked and answered . r the same reason that it begins in any one of the elements is partially prepared in advance by perforat-ing it with holes and filling the holes with oxide of lead. This kind of bat-tery may be used for cautery work, or for running such machinery as fansetc. It is heavy and not easily moved about. It is also an expensive kindof battery. This prepared element is called a grid. 36 THE ELECTRO-THERAPEUTIC GUIDE DENSITY AND DIFFUSIONWhat is ttnderstood by density and diffusion? Density and diffusion are terms used to refer to the mode of transmissionof the current through the patients body. They vary with the size of theelectrode. Where the current passes through a small electrode the currentis concentrated at the point of application, and therefore more dense. Witha larger electrode the lines of force are spread out more, or are diffused. The density and diffusion of a current is directly proportional to theconductivity of the conductor and the area of the contact By referring to the above sketch we can see that if the conductivity ofthe left hand conductor is the same at A, B and C then the density of thecurrent will vary in different places. The lines representing the current atA are closer together than they are at B, and at B more than at C. By re-ferring to the right hand sketch we see that the dense current at A beginstodiffuse at B, until at C, the point of contact, thecurrentis widely diffusedover a large area, and that the current is equally distributed over all partsof the surface at C. We can take advantage of this when we wish to apply a large dose toa sensitive surface. By spreading it over a larger area it divides the resist-ance, and lessens pain. POLAR AND INTER POLAR EFFECTSWhat are the polar and inter polar effects? We have shown the local action going on inside the cell, resulting inpolarization. It now remains to speak of the local polar, and inter
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Keywords: ., bookcentury1900, bookdecade1900, booksubj, booksubjectelectricity