2. Previous work on the enzymic hydrolysis of phloridzin shows that it is not hydrolysed by emulsin, but that it is hydrolysed by some other enzyme which occurs fairly freely in nature.

3. The difficulty in examining the enzymic hydrolysis of phloridzin lies in its very low solubility. It has been shown, in confirmation of earlier work, that emulsin is definitely without action on phloridzin at various values of pH and of temperature. This result is difficult to reconcile with the ß-glucosidic character commonly ascribed to phloridzin, and with the fact that emulsin hydrolyses (synthetic) phloroglucinol-ß-glucoside, of which phlorizin is regarded as a derivative.

4. Phloridzin is hydrolysed by a yeast maltase preparation, known to contain saccharase. Phloridzin is readily attacked by maltase-free saccharase at 30°C. and pH of 4.45. If the -glucase of the sucrose-splitting enzyme is (as stated) inactive under these conditions, then the enzyme responsible for the hydrolysis of phloridzin is ß-() fructosidase.

5. The sugar prepared from phloridzin differs from glucose in its specific rotation and in its action towards Bacillus pestis.