The Scholander pressure chamber is one of several devices used to study the water relations of green plants. For field work it can be used to rapidly measure leaf water potential, and for laboratory studies it can be used to determine the turgor and osmotic components of plant water potential.

A series of experiments were conducted on wheat leaves. A leaf was cut from the plant and placed in the cylindrical chamber so that its cut end protruded through an air-tight seal. When the chamber was pressurized to several atmospheres, water appeared at the cut end.

When the pressure was increased several more atmospheres, water flowed from the cut end of the leaf for 10 to 40 minutes. The total efflux was dependent on the water potential of the leaf. Efflux curves for the experiments were drawn by plotting the total water expressed as a function of time after the pressure increase. The total efflux was dependent on the water potential of the leaf. This dissertation is an experimental and mathematical analysis of the efflux curves.