Work, carbon dioxide excretion in relation to, 123 carbon dioxide excretion during, 111, 112 due to proteid decomposition, 58 effect of, on energy exchange, 109, 110, 113, 115 experiments on man, 110, 111, 112, 113, 114, 115, 116 heat production in, 110 influence of, on oxygen consumption, 126 influence of, on respiratory quotient, 126 nitrogen excretion during excessive, 127 nitrogen excretion during fasting in, 125 proteid decomposition in, 58 relation of diet to, 126 to energy exchange, 119 fats and carbohydrates to, 58 nitrogen excretion on proteid diet to hard, 123, 124 nitrogen excretion to proteid diet to hard, 122, 123, 124 relation of oxygen consumption to, 123 phosphorus excretion to, 123 sulphur excretion to, 123 respiratory quotient in relation to, 125 source of energy during fasting in, 125 views of Argutinsky on muscle, 123 views of Pflüger on muscle, 123 views of Voit on muscle, 59, 134 X Xanthin, 72 Xanthin oxidase, 73