The Spontaneous Oxidation of the Sugars.’

How does it happen that the proteids, carbohydrates and fats which ordinarily are oxidized by atmospheric oxygen at a very slow, or almost imperceptible rate, combine with oxygen with great rapidity in living matter? To answer this question I made the hypothesis that the total consumption of oxygen by the protoplasmic mixture is the sum of the consumptions of the various substances composing that mixture. If, therefore, we wish to know why sugar or any other substance burns rapidly in the living mixture, one way of finding out would be to discover what had to be done to that substance to make it burn rapidly outside of the cell. We might then infer that a similar thing was done in living matter and proceed to look for evidence that such a’process actually took place. I have, hence, been studying the spontaneous oxidation of various cell constituents in vitro and I began with the sugars. If glucose is dissolved in water, the solution sterilized, and left exposed to air or oxygen at room temperature the oxidation goes on at so slow a rate as to be practically imperceptible for long periods. Yet this same glucose burns rapidly in living matter. There are two ways in which with present chemical conceptions we may picture the mechanism of this acceleration: the active mass of the oxygen or of the sugar molecules, or of both is actually increased, or the speed of the reaction is accelerated by the formation of intermediate compounds. It may be