Keywords: Life in Motion Fig 67.png en Fig 67 ”Wiedemann's galvanometer much employed especially in Continental schools by physiologists The two outer coils are of low and the two inner coils are of high resistance The low resistance coils are used for thermal currents and the high resistance coils for the currents of living tissues A ring magnet is suspended by a long filament of silk and hangs in a copper box in the centre of the coils of wire On the rod carrying the ring-magnet and in the box above the coils we have a mirror which reflects a beam of light on to the scale Life in Motion or Muscle and Nervehttps //archive org/details/b21929786 John Gray McKendrick 1892 1926 Life in Motion book Galvanometers |