Experimental results described in the present paper confirm the hypothesis about cavitational nature of the ultrasonic capillary effect (UCE), which is an abnormally high rise of a liquid in a capillary under the action of ultrasound. In accordance with this hypothesis UCE is associated with the collapse of cavitation bubbles at the capillary entry. Bubbles collapse asymmetrically to form a jets directed to the capillary but-end. By getting into the capillary channel, every such a jet increments the height of the capillary rise. When summed up these increments result in the experimentally observed increase of the height and speed of the liquid rise in the capillary. Theoretical estimations based on this mechanism are in acceptable agreement with experimental results.
