208 



PRACTICAL PHYSIOLOGY. 



fxxxvu. 



say, 120 or 250 double vibrations per second, and adjust its 

 writing-style in the position formerly occupied by the style of the 

 muscle-lever. Set the fork vibrating, either electrically or by 

 striking it. Allow the pendulum to swing, when the vibrating 



250 DV. 



FIG. 126. Pendulum-Myograph Curve. S. Point of stimulation ; A. Latent period ; 

 B. Period of shortening, and C. of relaxation. 



tuning-fork will record the time-curve under the muscle-curve (fig. 

 126, 250 DV). All the conditions must be exactly the same as 

 when the muscle-curve was taken. 



FIG. 127. Spring-Myograph. 



(/?.) Varnish the curve, and measure its phases. Bring ordinates 

 vertical, a', 6', c', to the abscissa, and measure the " latent period " 

 (fig. 126, A), the duration of the shortening (B), the phase of 

 relaxation (C), and the contraction remainder. 



2. Spring-Myograph (fig. 127). The arrangements are exactly 



