Spiral condenser @museum.de

F: This weird-looking set-up can actually be used to distil spirits. What you're looking at here is a spiral condenser. No prizes for guessing where the name comes from.

M: The cooling tube is twisted into a spiral. The advantage of this design is that it increases the surface area of the tube and hence the cooling effect.

F: However, the spiral condenser also has a serious disadvantage: the inside of the tube is extremely difficult to clean, and verdigris tends to accumulate in there. Hence the verse, loosely based on Friedrich Schiller.

M: "To wake the lion may prove fatal,

The tiger's tooth may be your bane,

But for the most horrific nightmare,

lick the back end of the destiller,

where verdigris may yet remain!

F: Liquor distillers used a mixture of sand, water and ash for cleaning purposes. The condenser coil would be filled with this mixture and then given a good shaking. Ultimately, though, the spiral condenser wasn't an ideal solution. It was overtaken by other developments.