The household medical adviser. A complete, popular-scientific work of reference ... compiled from the most recent recognised system of prevention and cure ... with over 320 illustrations, coloured plates and unfolding anatomical models / by H.Muller. M.D.

  • Müller, H.
Date:
1900
Catalogue details

Licence: In copyright

Credit: The household medical adviser. A complete, popular-scientific work of reference ... compiled from the most recent recognised system of prevention and cure ... with over 320 illustrations, coloured plates and unfolding anatomical models / by H.Muller. M.D. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    this shadow on a photographic plate. After this brief preliminary mention of how the Rontgen rays were discovered, we may turn our attention to the complete apparatus necessary for making use of this wonderful discovery. The apparatus consists of two parts. (1) An apparatus that can give an electric current of a very high tension. (2) The discharging apparatus, that is to say the tube, through which the current is sent. In order to obtain an electric current of very high tension it is best to use what is called a RuhmkofF induction apparatus. As has been already explained in the section devoted to electric therapeutics, an induction apparatus is one by means of which we can obtain by induction from a primary current of small tension but proportionately great strength, a secondary current of high tension but less strength. Apparatus of this kind brought to a high degree of perfection were first made by Ruhmkoff in Paris, and are still known by his name. Now, the greater the tension of the inductor the larger and longer are the electric flashes which it can give ; and we describe the induction apparatus by the extreme length of the electric flashes obtained from it, speaking of an inductor of 20, 30, 40, or even 50 or more centi- meters, that is one capable of giving us an electric flash of that length. We usually procure the primary current from accumulator batteries, as these batteries give us the most constant and most trustworthy currents. Of these accumulator batteries I shall attempt here only such an explanation as may acquaint the reader with what is most necessary to be understood. We know that the conducting fluid which we place in a vessel (technically called a cell) in which we plunge two electrodes, that is to say two plates of the same metal, and then pass an electric current through them, is separated into its elements. These conducting fluids are in general solutions of acids, or salts, and water; and the phenomenon of decomposition of the fluid which takes place is called electrolysis. In all these cases of electrolysis certain changes take place simultaneously in the electrodes, and the two pieces of metal which we have used are affected in very different manners, so that we find in the fluid two metalic bodies differing in a certain degree from each other, which are now capable of reciprocally producing an electromotor effect. In other words the cell has become a galvanic element which is capable of producing an electric current. This process is called the polarization of the electrodes, and the current which is obtained from these polarized electrodes a polarization current. A polarization element is called a