Directions for classwork in experimental physiology / by Sir Edward Sharpey Schafer.

  • Sharpey-Schäfer, E. A. (Edward Albert), Sir, 1850-1935.
Date:
[between 1915 and 1935?]
Catalogue details

Licence: In copyright

Credit: Directions for classwork in experimental physiology / by Sir Edward Sharpey Schafer. Source: Wellcome Collection.

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    duced at the ends of the wires. With one of these ends (a) another wire is connected ; this forms part of the experimental circuit through which a portion of the cell current is to be conducted ; this circuit is completed through a wire attached to a rider (r) which slides along the rheochord wire. Fig. 20.—Diagram of the Oxford form of rheochord. a, b, Rheochord wire zig- zagged upon a mahogany board, marked by cross lines into hundredths ; r, rider. When r is in contact with b the whole difference of potential between a and b—which depends upon the e.m.f. of the cell or battery and the resistance of the rheochord wire relative to that of the experimental circuit—is operative in producing a current through the preparation. When r is at the middle of the rheochord wire only one-half of this difference of potential comes into play, and so in proportion to the distance between a and r as compared with the