Recently while studying the effect of mucin in the treatment of peptic ulcer, we noticed that patients responded differently to different batches of the substance. With some samples of the material the patients appeared to be helped, and with others they seemed definitely to be harmed. When we averaged the free gastric acidity found in all the cases treated with mucin, we found it to be 31 points higher than it was in a group of patients treated with the usual diet and alkaline powders. In some cases in which the patients were receiving 100 or more Gm. of mucin each day the gastric acidity rose much as it does after an injection of histamine.
These observations led us to make an investigation into the possible causes of the bad effects obtained with some batches of the substance. We began using mucin test meals, in which from 50 to 100