54 



LABORATORY GUIDE IN PHYSIOLOGY. 



pieces of cork and held by an extra support. A 

 "universal" clamp holder is a most desirable acces- 

 sory to this apparatus. 

 The electrical apparatus should be set up as shown in 



PL II., Fig. 4. 



With this arrangement either electrode e or electrode 

 e' may be made the anode, the experimenter needing only 

 to reverse the commutator bridge to reverse the position 

 of anode and kathode. 



FIG. 10. 



FIG. 10. Double myograph. Described in the text 

 under VIII=3. 



The recording drum or kymograph should rotate 

 rapidly. The recording points of the myograph levers 

 should be adjusted so that the point of the upper one 

 touches the drum vertically over the point of the lower 

 one. Adjust the time marker so that it will indicate the 

 time of making and breaking the circuit, i. e., so that it 



