Dental electro-therapeutics.

  • Sturridge, Ernest, 1864-1948.
Date:
1914
Catalogue details

Licence: Public Domain Mark

Credit: Dental electro-therapeutics. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    quence that a painful shock is experienced when each cell is added to the circuit. Most of these batteries are made and sold by instrument makers with only the controller, but a rheostat should be insisted on if good results are desired. Fig. 34 Galvanic battery. The current from a battery of 18 or 24 Leclanche cells works out according to Ohm's law as follows: presuming the E. M. F. of each cell to be 1.5 volts, which is very nearly correct, and the internal resistance (r) to be 3 ohms, with a patient in circuit of 1500 ohms' resistance (R) the current strength (C) would be E._M. F. R +r~ 18 cells X 1.5 volts R1500 + (r3 X 18) = °017 amP6rea = 17 ma.