The Liebig condenser is the most basic water-cooled design. The inner-tube is straight, making it cheaper to manufacture. Though named after the German chemist Justus Baron von Liebig, he cannot be given credit for having invented it because it had already been in use for some time before him. However, it is believed that he popularized the device.
The true inventors, all of them inventing it independently, were the German chemist Christian Ehrenfried Weigel in 1771, the French scientist, P. J. Poisonnier in 1779, and the Finnish chemist Johan Gadolin in 1791
The Liebig condenser is much more efficient than a simple retort due to its use for liquid cooling. Water can absorb much more heat than the same volume of air, and its constant circulation through the water jacket keeps the condenser's temperature constant. Therefore, a Liebig condenser can condense a much greater flow of incoming vapour than an air condenser or retort.
The set up
A, is a stoppered retort, the neck of which fits into the tube of a Liebig's condensor (B), which consists of a glass tube (C), fitted by means of corks into a glass, copper, or tin tube (D), into which a stream of cold water is passed by the funnel F. the heated water running out through the upper tube F. The water furnished bv the condensation of the steam passes through the quilled receiver G, into the flask H.Heat is gradually applied to the retort by a ring gasburner.