Abstract: Experiments were carried out on 3 dogs with a Thomas' modified Pavlov pouch. The gastric juice was collected for a period of 4 hours. Its acidity was titrated by 1/10 N NaOH and the digestive power was examined by means of Mett's method. In 2 dogs, a single subcutaneous injection of 20mg/kg of corydalis B had no marked influence on gastric secretion. When the dose was raised to 40 mg/kg/day and continued for 12 days, the gastric secretion, its acidity and digestive power did not show significant change, but in a few days the amount of first hour secretion was decreased. In another dog a single dose of 80 mg/kg caused a considerable reduction in the total amount of gastric secretion, especially in the first three hours. The gastric acidity (both total and free) and digestive power were also depressed. In two dogs corydalis B was administered subcutaneously at the dosage of 40 mg/kg/day for 12 days. The hypnosis occurred 5—20 minutes following injection and was maintained for about 80 minutes. This action was weakened after several injections; thereafter it might be somewhat recovered, and finally, on the 11—12th days a new drop in the drug potency was observed. It is thus suggested that the tolerance to corydalis B may be developed. A single subcutaneous injection of 20 or 80 mg/kg of corydalis B and multiple injections of 40 mg/kg produced no significant influence on respiration of the above-mentioned 3 dogs.