The Effect of Changes in Regime upon the Urinary Alkaline Tides in a Normal Individual.

In 1912 Henderson and Palmer (1912) introduced a technique for determining the pH of the urine and applied it to the study of twentyfour-hour specimens from 222 normal and pathological cases. Their observation showed a rarge of pH from 5.0 to 7.4. They also observed that the pH of the urine rises to some extent following a meal. The pH curve of normal urine was also studied by Hasselbalch (1912) who reported a fall in pH immediately after each meal followed by a rise to a maximum about three hours later. Fiske (1921) confirmed the existence of this rise in pH after meals and observed pH values during the alkaline tide as high as 7.7. He studied also the phosphate excretion during the period of the alkaline tide. Hubbard, Munford and Allen (1924) observed that the alkaline tide occurred only in individuals who showed presence of free HCl in the stomach during digestion. Higgins (1914) and Erdt (1915) found a rise of alveolar pCO2 during digestive activity. Van Slyke, Stilhman and Cullen (1917) confirmed this observation and found that the plasma bicarbonate in some cases increases slightly, in others not. Dodds (1921) and Dodds and McIntosh (1923) observed a rise in the CO2 content of the blood and in alveolar pCO2 about one-half hour after meals followed by a secondary fall in both at the time the urinary alkaline tide occurs. Leathes (1919) found that normal active individuals given water without food at 8 a.m. showed an increased urinary alkalinity during the morning hours. He attributed the alkalinity to increased pul-