The effect of halogen salts on tryptic digestion.

THE effect of halogen salts on salivary and peptic digestion has been described previously [Clifford, 1925; 1927; 1928], and in this paper an account is given of their action on tryptic digestion. The earliest work on the subject appears to be that of Pfeiffer [1884] who found that, with the exception of sodium carbonate, all salts, especially sodium chloride, retard tryptic digestion. Later, Weiss [1904] found that sodium chloride in strong concentration retarded tryptic action whilst in weak concentration it accelerated it. With sodium bromide and iodide he obtained similar though less marked results, and the potassium salts acted in the same way as the sodium salts. Unfortunately, his experiments were carried out using solutions of equal percentages and not of equal molecular concentrations, and this makes the results difficult to compare. Robertson [1906] found that all salts accelerated, but stated that chlorides, nitrates, and sulphates accelerated tryptic action least, as compared with cyanides and salts of fatty acids. In the experiments to be described an attempt was made to investigate the action of equimolecular solutions of halogen salts on the tryptic digestion of protein.