III. On the estimation of the amylolytic and proteolytic activity of pancreatic extracts

Abstract

The degree of activity possessed by preparations of the soluble ferments cannot be ascertained by direct weighing and measuring. The agents to which they owe their power have in no case been obtained in a state of isolation and purity. These agents are known to be indissolubly united with some form of albuminoid matter, and we are constrained to speak of them as if they really were albuminoid bodies. But their mode of action suggests an affinity with the imponderable forces, and points to the conclusion that the relation which these agents bear to their organic substratum is analogous, or at least comparable, to the relation subsisting between a mass of protoplasm and the vital endowments with which it stands possessed. The activity of preparations of the soluble ferments can only be gauged by their capacity for work. But inasmuch as there is in them no power of growth and multiplication, the amount of energy with which they are endowed is strictly limited, so that when the capacity for work existing in a given liquid or solid preparation of one of these ferments has been ascertained, and has been put into due expression, the amount of energy in a certain quantity of the preparation can be counted in grams or cubic centimetres like that of any other chemical agent.