PEPSIN  , an

enzyme or ferment obtained by drying the mucous lining of the fresh and healthy stomach of a pig, sheep or calf . As used in medicine it consists of a light yellow-brown or white powder or of pale yellow translucent grains or scales . It is only slightly soluble in water and alcohol . Pepsin is used to help gastric digestion in old people and in those in whom there is a deficient secretion of the gastric juice . It is useful in chronic catarrhal conditions of the stomach, the dyspepsia of alcoholism, and in gastric ulcer and cancer of the stomach . Pepsin digests the albumens but is useless in the digestion of fats or carbohydrates . It may also be used to predigest albuminous foods . The following is a method of peptonizing beef . Take } lb of minced raw lean beef, 1 pint of water containing o•2 % of hydrochloric acid, place in a jar with 3o grs. of pepsin, set in a warm place at t to° F. for 3 hours, stirring occasionally . Then quickly boil it . It is usually unnecessary to strain it, as the meat is reduced to a fine almost impalpable powder which is readily assimilated . Many varieties of proprietary peptonizing tablets are on the market and are convenient for the preparation of peptonized milk .

The following is a method of preparing it . Take a clean

glass quart bottle, pour in a pint of perfectly fresh cold milk, then add a teacupful of cold water in which a peptonizing tablet has been dissolved . Submerge the bottle in a can of water at ioo° F. for from 5 to to minutes, take out the bottle and place on ice to prevent the further action of the pepsin . If no ice is convenient bring the milk to a boil for the same purpose . If the action of the pepsin be continued for a much longer period the milk becomes bitter to the taste from the development of excess of peptones . Predigested foods should not be used over a long period or the digestive functions of the stomach may atrophy from disuse . Pancreatic solution, derived from the pancreas of a pig digested in alcohol, has the power of converting starch into sugar, and albumen and fibrin into peptones . It only acts in an alkaline medium and at a temperature under 140° F . If used to peptonize milk sodium bicarbonate should be added . Many commercial preparations are on the market . Trypsin, the principal ferment of the pancreas, also changes proteids into peptones .