. again. Make it long enough, and leave it alone to do its thing. What do we end up with? The first thing to note is that the main difference between a pot still and this column is that gravity plays. trying to do. It is a basic description only, and those with rigorous scientific leanings should feel free to contact me if they find any alarming errors of fact. However, I ask that criticism be. have seen at school. Take a long glass tube and fill it with mercury. Upend it in a beaker of mercury and if the tube is long enough then it will be seen that the mercury will be held up in the