CHAPTER XVII. 



THE MYOGRAPHION. 



THE registration of muscular movements has been 

 accomplished with the aid of an. instrument called the 

 myographion. An extremely complicated instrument 

 was devised by Helmholtz for the purpose of measuring 

 the rapidity of the nerve current. The simple 

 myogvaphion of Pflueger is shown in Fig. 87. It con- 

 sists of a mahogany base s, from which rise brass 

 pillars a, which carry 

 the double lever 6. From 

 the forward end of b 

 hangs a rod with a steel 

 point projecting against 

 the glass plate p. The 

 weight of this part of the 

 lever is counter-balanced 

 by m. From the base rises 

 a brass column z, hold- 

 ing the forceps, in which 

 the nerve-muscle prepara- 

 tion is caught. Through 



the tendo Achilles of the Fig. 87. Simple Myographion. 



muscle is passed a hook, 



attached to c of the lever. From the under side of the 

 lever hangs a scale-pan for weighting the muscle. The 

 brass pillar supports a glass chamber in which the muscle 

 may be kept moist. If the glass plate is smoked, 

 and the steel point projects on to it, then, a basement 

 line having been obtained by drawing the plate in 

 front of the point, on the muscle contracting a line is 

 drawn, and the extent of contraction can be measured 



