The action of enzymes fascinated mankind long before they were rec ognized for the complex chemicals that they are. The first application of these remarkable compounds to produce ethanol by fermentation is lost to antiquity. Payer and Persoz (Ann. Chim. Phys., 53, 73 (1833ii)) appear to have provided the first step toward understanding this com plex area when they reported the isolation of diastase in 1833. These workers showed that diastase could catalyze the hydrolysis of starches to sugars. Somewhat earlier Kirchhoff (Schwigger's Journal, 4, 108 (1812)) had shown that a small amount of...