605 to pepsin. Pepsin is completely destroyed by trypsin in alkaline solution and almost entirely so by 0' 01 per cent. of sodium hydroxide. Diastase is rendered inactive in nine hours by 0 -1 per cent, of sodium hydroxide, it is almost entirely destroyed by 0' 009 per cent. of hydrochloric acid-i.e., in a solution containing one-twentieth the acidity of the gastric juice-and its activity is weakened by pepsin even in neutral solution. But diastase is not affected