The Effect of Halogen Salts on Peptic Digestion.

IN a previous paper [Clifford, 1925] the effects of the halogen salts of sodium, potassium, ammonium, and calcium on salivary digestion were described. These salts were found to vary in their action on ptyalin, some delaying digestion, others being inert, and some increasing the speed of reaching the achromic point. It was thought advisable to continue the investigation with other enzymes, and the experiments to be described give results obtained as to the effects of halogen salts on the action of pepsin. Very little work appears to have been done on the influence of salts on peptic digestion. Hamburger and Halpern [1916] found that sodium chloride in "high concentration" only (0-25 %) inhibited peptic activity, whilst in " low concentration " (0.170 %) it accelerated it. They obtained similar results with sodium phosphate. Rona and Kleinmann [1924] investigated the effects of the chlorates, nitrates and sulphates of various metals, and using a nephelometric method found that all the salts hastened peptic digestion if the PH of the solution were high and the concentration of the salts low, whilst the reverse was the case if the PH were low or the salts more concentrated. Cole [1926, p. 248] says "neutral salts inhibit the action of pepsin, this being in marked contrast to the influence of sodium chloride on ptyalin." Bayliss [1924] states, as a generalisation on ferments, that "neutral salts also have an influence, as a rule, of a favourable kind."