Some new methods and some established ones have been applied to studies of salivary glands in health and certain disease states. A technique of recording the pattern of salivary flow has made it possible to collect saliva samples accurately at several different but constant flow rates. The effect of varying salivary flow rate on the parotid and submandibular concentrations of electrolytes, iodide, uric acid and also the activity of carbonic anhydrase has been demonstrated and the normal ranges defined. It is important to relate the concentration of some salivary constituents, e.g. iodide, to the plasma level.