“…Such Thiry fistulas were prepared in dogs. Sodium retention was induced with deoxycorticosterone acetate, since the abnormal conservation of sodium by the kidney, colon, salivary gland and sweat gland of the oedematous individual may be simulated in normal men by administration of deoxycorticosterone (Conn, 1949;Berger, Quinn & Homer, 1951;White, Entmacher, Rubin & Leiter, 1955). With the use of radio-isotopes the unidirectional fluxes of sodium and of potassium were measured across the mucosa of various segments of the dog intestine before and after the administration of deoxycorticosterone.…”