HYDROGEN IONS-YESTERDAY, TODAY AND TOMORROW

　Hydrogen is the primordial element of the universe and ionized hydrogen, the proton, plays an essential role in the functioning of all living organisms. In the cell, protons are donated and accepted in the metabolic reactions that constitute the "fire of life"；in the total organism, the concentrations of these hydrogen ions closely condition, and are conditioned by, the function of many organs. The well-regulated ebb and flow of this protonic tide is the essence of acid-base balance.