Three samples of washed erythrocyte suspensions in pure plasma were prepared at hematocrit (HCT) = 35, 45, and 55%. (A) The conductivity of blood increased slightly during the first minute of observation and then decreased for more than 1.5 h. The conductivities of the disaggregated erythrocyte suspension were σ = 0.588, 0.468, and 0.355 S/m, at HCT = 35, 45, and 55%, respectively. The conductivity of the deposit on the bottom of the chamber was approximately 0.175 S/m at the end of the sedimentation, regardless of the initial HCT. (B) Initial changes in blood conductivity at HCT = 35%. The maximum value of the initial increase in conductivity was about 0.036 S/m at 18s. (C) The maximum value of the initial increase in conductivity was 0.028 S/m at 31 s (HCT = 45%). (D) The maximum value of the initial increase in conductivity was 0.027 S/m at 60 s (HCT = 55%).