Electro-therapy in gynæcology / by Samuel Sloan.

  • Sloan, Samuel, 1843-1920.
Date:
[1917]
Catalogue details

Licence: Public Domain Mark

Credit: Electro-therapy in gynæcology / by Samuel Sloan. Source: Wellcome Collection.

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    ELECTRO-STATICS? OR ELECTRICITY AT REST Electrical attraction and repulsion; induction; the electroscope, its principles and mode of action; conductors and insulators; Leyden jar, construction of; meaning of dielectrics; capacity of Leyden1 jars; electro-positives and electro-negatives in metals and in solutions ; electrolytes ; methods of conduction in metals and in liquids ; relation of electricity to chemistry; relation of electricity at rest to electricity in motion. For the study of this department of electricity what is called an electroscope is essential. This instrument can reveal the presence of the most minute quantity of electricity, as well as show whether the charge is a positive or a negative one. Fig. 1, p. 6, represents an ordinary gold-leaf electroscope. To understand the principle of action of this instrument one must bear in mind the following points. When a body becomes charged with electricity it becomes capable of attracting small light bodies in its neighbourhood, whether the charge be positive or negative. If one of these light particles be permitted to come into actual contact with the electrically charged substance, it becomes actually charged; and, instead of being now attracted, it is repelled : the law being that similarly charged bodies repel, and dissimilarly charged bodies attract, each other. The attraction of light bodies by an electrically charged substance is strictly electrical. When a small ball of elder pith is brought near a positively charged glass rod, the electrical equilibrium of the former is disturbed. By “induction a negative charge appears on the side next the glass rod ; a positive charge equal to it in amount retreating to the further side. Thus the electrical charges
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