Electricity in the diagnosis and treatment of diseases of the nose, throat and ear with 161 illustrations / by W. Scheppergrell.

  • Scheppegrell, William, 1860-1928.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Electricity in the diagnosis and treatment of diseases of the nose, throat and ear with 161 illustrations / by W. Scheppergrell. 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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    In this form of electro-therapeusis, in which a small current of high potential is needed, a large number of accumulators would be required, and, as the efficiency of these batteries de- pends upon the regular charging and discharging of the cells, their employment would not only be expensive, but would also cause an unnecessary amount of labor and inconvenience. When it is considered that an ordinary salammoniac battery, such as the Gonda, Law and others, which can be purchased for about 60 cts. each, and some of the dry cells at a still lower price, will answer effectively in galvanic and electrolytic work for as long as one or two years with little or no attention, the impracti- cability of substituting the bulky and expensive storage cell, with the attention that it requires for charging, etc., will be easily seen. THERMO-ELECTRIC BATTERIES. Thermo-electric batteries may be used to generate a galvanic current, but it has been found that they are practicable only in currents which require a light electro-motive force, as for the electro-cautery, telegraphy etc. They are rarely used in electro- therapeutics. A convenient thermo-electric battery has recently been introduced, the heat being generated by means of oil or gas. It gives sufficient current for small incandescent lamps and fan motors. DYNAMOS. The current generated by dynamos is now used so extensively that it has, to a large extent, replaced the former methods of generating electric energy. The most common method of utilizing the constant current from dynamos is the Edison cur- rent used for incandescent lighting. As there are four varieties of current used for electric lighting, it is well to understand which of these can, and which cannot, be used. There is first the constant potential current, in which the volts are constant, but the amperes vary according to the number of lamps in the circuit. The Edison is the type of this current, and this is the one which offers the greatest amount of usefulness in electro-therapeutics. Then there is the direct current, in which the amperes are constant, but in which the volts vary according to the number of lamps in the circuit. If. for instance, there is a current of ten amperes, and each lamp in the circuit