RELATION OF OXIDATION TO METABOLISM

The idea that respiration directly causes or regulates metabolism was abandoned by physiologists many years ago, especially as a result of the investigations of Voit and Pflüger, who by independent methods demonstrated the untenability of this view. The intake of oxygen does not cause metabolism, but on the other hand the chemical reactions going on in the organism determine the amount of oxygen to be absorbed. The combustion processes in the living body may proceed for some time quite independent of the extent to which oxygen is supplied. Even in the days of Lavoisier it was appreciated that the utilization of oxygen in the organism is not enhanced by a greatly increased supply in the respired air. The breathing of compressed air or of pure oxygen leaves the combustion processes essentially unaltered. Metabolism regulates the respiration. As Lusk has expressed it, the metabolism of the tissues, through its oxygen requirement