“…The pH in the normal and in the ulcerated duodenum has been reasonably well documented (Berk, Rehfuss, and Thomas, 1943;Rovelstad, Owen, and Magath, 1952;Rovelstad, 1956;Tomenius and Williams, 1960;Rovelstad and Maher, 1962;Andersson and Grossman, 1965;Bircher et al, 1965;Moore and Scarlata, 1965;Archambault et al, 1967). There is disagreement, however, on the nature of the rapid variation in pH in the duodenum (Archambault et al, 1967).…”