[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
January 7, 1933


JAMA. 1933;100(1):44. doi:10.1001/jama.1933.02740010046012

A century has passed since Payen and Persoz, in 1832, prepared from malted barley an extract that converted starch into sugar somewhat as strong acids do. This conversion was carried out even though living cells were not present. The effective agent was designated diastase—an expression until recently applied by French writers to all enzymes. Later came the discovery of the proteolytic agent pepsin, in the gastric juice, explaining how meat could be digested in glass vessels as it is in the living stomach. Presently it became customary to distinguish between the organized ferments, that is to say, living organisms such as yeasts and bacteria, and the so-called unorganized ferments. The latter were evidently chemical substances that are the products of living cells. Forty years ago a writer1 described them as remarkable substances invested with the power of producing molecular rearrangements in products with which they come in contact. In