[Dynamics of sodium and hydrogen ionic activity as a criterion for determining time of death]

The paper is concerned with a procedure for determination of the death onset. The time course of changes in the activity of sodium and hydrogen ions in the blood, CSF and vitreous body was examined in 42 rabbit cadavers. The animals were killed by air embolism. Before material collection the rabbit cadavers were stored at a temperature of 17-20 degrees C and a relative humidity of 40-60%. The material was collected promptly after the killing (0 h--control) and then 2, 4, 6, 12, 18, 24, 36 and 48 hours after the death onset. The activity of sodium ions was determined potentiometrically with the use of an ion-selective sodium glass electrode, whereas that of hydrogen ions with the aid of a set up manufactured by the Radiometer Company. The results indicate the advisability of using the procedure described for studies on section material to devise criteria of expert evaluation of the time of the death onset.