Electro-physiology (1896-98) Electro-physiology electrophysiolog01bied Year: 1896-98 TV ELECTROMOTIVE ACTIOX IN MUSCLE 387 tachy graphic ' method, as described above) published a yraphic record of the gastrocnemius action current, which, on leading off from the tendo achilles and from a point proximal to the nervous equator, gives double-topped curves, in which the first descending phase is succeeded by a second, weaker, ascending variation, after which the magnet returns to its zero with some insignificant deflections (Fig. 122). This dissimilarity is apparently due to a partial superpositio
Electro-physiology (1896-98) Electro-physiology electrophysiolog01bied Year: 1896-98 TV ELECTROMOTIVE ACTIOX IN MUSCLE 387 tachy graphic ' method, as described above) published a yraphic record of the gastrocnemius action current, which, on leading off from the tendo achilles and from a point proximal to the nervous equator, gives double-topped curves, in which the first descending phase is succeeded by a second, weaker, ascending variation, after which the magnet returns to its zero with some insignificant deflections (Fig. 122). This dissimilarity is apparently due to a partial superposition of the two phases ; the excitation has not entirely passed the upper lead-off before it reaches the lower. The gastrocnemius curve of electrical variation is even more complicated on lead- ing off from the centre and tendo achilles, as in the observa- tions of Lee which we have frequently referred to, in which the more sluggish galvanometer is replaced by the sensitive capillary electrometer. The rheotome method can also be applied here. The curve (Fig. 123, a) corre- sponds with a triphasic varia- tion, its two negative sections being separated b}r a double- topped, positive, and very steep segment. The duration of the entire process amounts to 0'26 sec., a value which we have seen to be approximately equi- valent to the duration of a twitch in the muscle. The wave of variation in the sartorius, on the other hand (when led off from the middle and end of the muscle), was found by Lee to be diphasic, no conspicuous decrement being visible in the fresh, uninjured muscle, Both sections exhibited a tolerably symmetrical figure (Fig. 123, b). If, however, the tendon end of the muscle is injured ever so slightly, the first (' negative ') phase prevails, and the second may disappear entirely, as shown by the lower curve of the same figure. In this case the variation, which is now monophasic, does not appear perceptibly shorter than the sum of the two earlier phases, which again impl
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