208 



PRACTICAL PHYSIOLOGY. 



[XXXVIl. 



say, 1 20 or 250 double vibrations per second, and adjust it-s 

 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 



i 



f 



r 



250 DV. I 



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

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



tuning-fork vnll 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. 



FlO. 127.— Spring-Myograph. 



(7l) Varnish the curve, and measure its phases. Bring ordinates 

 vertical, a', h\ 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 



