THE INFLUENCE OF SECONDARY RESISTANCE 75 
are constants. This formula has been found to hold 
in all of the several hundred experiments, in which it 
has been applied. The value of the constant /3 in any 
12 
10 
4000 
8000 
16000 
20000 
FIG. 16. Showing that the curve of increasing stimulus against 
increasing resistance is a straight line. Abscissae represent values of Z; 
ordinates represent resistances in ohms. 
given experiment can be determined geometrically by 
producing the curve to where it cuts the ordinate for 
zero resistance. According to Fig. 16, the value of /3 
