An essay on electricity : explaining the principles of that useful science, and describing the instruments, contrived either to illustrate the theory, or render the practice entertaining : illustrated with six plates. To which is added, a letter to the author, from Mr. John Birch, surgeon, on the subject of medical electricity / by the late George Adams.

  • Adams, George, 1750-1795.
Date:
1799
Catalogue details

Licence: Public Domain Mark

Credit: An essay on electricity : explaining the principles of that useful science, and describing the instruments, contrived either to illustrate the theory, or render the practice entertaining : illustrated with six plates. To which is added, a letter to the author, from Mr. John Birch, surgeon, on the subject of medical electricity / by the late George Adams. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    may be made: 1. That what is attracted or re- pelled by the one^ is also attracted and repelled by the other; whereas, in the foregoing instance, what the one attracted, the other repelled. 2, That no sparks will pass between two conductors equally electrified with the same power, though they will pass continually between two electrified with dif- ferent powers. 3. Connect the two conductors that arc before the cylinder, and sparks may be taken from them, which cannot be done from the others when they are united. ' The conductor connected with the cushion is said to be negatively electrified. The conductor placed before the glass cylinder is said to be positively electrified.* These experiments, if the rubber be insulated, may be easily exhibited by one conductor, by means of the two directors with glass handles, * Hence every electrical machine, with an insulated rubber, may be considered as acting in a three-fold manner. 1. Asa machine producing negatwe electricity; by connecting the prime conductor to the earth by a chain, and taking the fluid from the cushion or rubber. 2. As a machine positive electricity. To effect this, make the rubber communicate with the ground by a chain, and take‘the fluid from the conductor. 3. As communicating the action of both powers at once. In this case, the rubber and conductor must both be insulated, and the substance to be electrified placed between two directors coi^- jiected with them.