A new stimulating apparatus which can generate lineally increasing current with variable increasing rate and variable voltage was devised. With this apparatus, smooth muscle of ureter (guinea pig) was stimulated, and threshold voltages (V) and excitation times (t) were measured. V-t relation was hyperbolic, and no“Einschleichen”was observed. There was, therefore, no critical gradient of stimulating current, that is, even by very slowly increasing current could be excited this muscle, when it reached to rheobasic voltage.
