APPENDIX C. 



341 



FIG. 12. 



12. THE RHEOCORD. h. Dubois-Raymond's Rheocord. b. The 

 simple rheocord as shown in figure 12. c. The Oxford rhecord. 



FIG. 13. 



13. ELECTRODES. Figure 13 shows: a. Hand-electrodes of insu- 

 lated copper or platium wires for use with induced currents, b. Non- 

 polarizable electrodes, variously constructed. For description see text. 



