in this discontinuous extraction process, the extraction solvent inside the boiling flask is evaporated and re-condensed in the distillation column above. it then falls down onto the solid material requiring extraction. the chamber containing the solid material is connected to the boiling flask below by a syphoning mechanism seen in the pythagorean cup, which allows the chamber to fill to a point, at which it will empty its contents and start to fill again and the extracted compounds will accumulate in the boiling flask below.