Note 30 — Chapter VI · Digestion.

Preparation of Artificial Gastric Juice. (a) Take part of the cardiac end of the pig’s stomach, which has been previously opened and washed rapidly in cold water, and spread it, mucous surface upwards, on the convex surface of an inverted capsule. Scrape the mucous surface firmly with the back of a knife blade, and rub up the scrapings in a mortar with fine sand. Add water, and rub up the whole vigorously for some time, and filter. The filtrate is an artificial gastric juice. (b) From the cardiac end of a pig’s stomach detach the mucous membrane in shreds, dry them between folds of blotting-paper, place them in a bottle, and cover them with strong glycerine for several days. The glycerine dissolves the pepsin, and on filtering, a glycerine extract with high digestive properties is obtained. These artificial juices, when added to hydrochloric acid of the proper strength, have high digestive powers. Instead of (a) or (b) use the artificial pepsin prepared for the market by the wholesale manufacturers of such goods.