A study has been conducted of the leaching and ion exchange behavior of ashed and unashed human bone. It has been shown that absorption of uranium does not depend on the presence of organic material in bone. High levels of the element in archaeological bone samples thus reflect inorganic ion exchange which could, in principle, continue indefinitely. The easier loss of chlorine than sodium has been shown not to be an indication of the mummification of archaeological remains. The observed fixation of chlorine in bone by ashing has not previously been reported.