Page:Life and death (1911).djvu/149

 liquids alone are subjected to oxydizing transformations, to nutritive metabolism. The accelerated evolution, which Liebig considered as an exceptional case, was to C. Voit the rule.

Current Ideas as to the Rôle of Foods.—The ideas of to-day are not those of Voit; but they do not, however, differ from them essentially. We no longer admit that the greater part of the ingested and digested albumen remains confined in the circulating medium external to the anatomical elements. It is held, with Pflüger and the school of Bonn, that it penetrates the anatomical element and is incorporated in it; but in agreement with Voit it is believed that a very small part is assimilated to the really living matter, to the protoplasm properly so called; the greater part is deposited in the cellular element as reserve-stuff. The material, properly so called, of the living machine does not undergo destruction and reparation as extensively as our predecessors supposed. There is no need for great reparation. On the contrary, the physiological activity consumes to a great extent the reserve-stuff. And the greater part of the food, after having undergone suitable elaboration, serves to replace the reserve-stuff destroyed in each anatomical element by the vital functional activity.

Experimental Facts.—Among the facts which brought physiologists of the school of Voit to believe that most foods do not get beyond the internal medium, there is one which may well be mentioned here. It has been observed that the consumption of oxygen in respiration increases notably (about a fifth of its value) immediately after a meal. What does this mean? The interval is too short for the digested