A piece of laboratory glassware consisting of a central pipe with a cold water jacket around it. Vapour is passed through the central pipe, while cold water passes against gravity through the water jacket.
The condenser can be employed in a diagonal (\) position, causing the condensate to trickle out of the end of the tube, or in the vertical position, where the condensate trickles back into the vessel it came from. The latter is used to reflux reactants together.
It was named after its inventor, Justus von Liebig.