Electricity in the diseases of women : with special reference to the application of strong currents / by G. Betton Massey.

  • Massey, G. Betton (George Betton), 1856-1927.
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Electricity in the diseases of women : with special reference to the application of strong currents / by G. Betton Massey. 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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    are as follow: When the meter is being transported the needle should be arrested b}r turning the knob, K, until it no longer moves. When about to use it, release the needle by a reverse movement of the knob, when it will be seen to swing freely on its pivots. If the needle does not settle at the 0 of the scale when it comes to rest, it is evidence of the displacing power of the earth's mag- netism at that particular spot, and should be remedied by raising or lowering the case by means of the adjust- ing screw, S, until the index is exactly at zero. The scale on this instrument is divided into ten units from zero in either direction. When the double switch, M, at the base of the instrument points to the figure 1 in front of it, the figures of the scale indicate a milliam- pere each. If this switch points to 10 the scale reading is to be multiplied ten times. If it points to 100- the scale is to be multiplied one hundred times. Thus, if the switch points to 1 and the needle indicates 3 on the scale, there is a current of three milliamperes in the cir- cuit ; if the switch points to 10 and the needle to 3 there are thirty milliamperes ; if the switch points to 100 and the needle to 3 there are three hundred milliamperes. When using currents of less than ten milliamperes, therefore, the switch, M, should point to 1; when less than one hundred are to be used it should point to 10, and when over one hundred it should point to 100. Before turning on the current alwa}'s be sure that the needle is free. Directions for using the Mcintosh meter (Fig. 6):— 1. Release the indicator b}^ sliding the button, D, to the right. 2. Turn the instrument so that the indicator points