A compact fractionation unit for distilling small quantities in a vacuum, and for ordinary separation. The indents are positioned to cause the vapor to follow a spiral path, adding to the efficiency of the unit. By use of the three-way stopcock, a manifold arrangement is achieved, making it possible to remove receivers without disturbing the equilibrium of the system. 10/30 joint at top is for 25 mm immersion thermometer. All other joints are 14/20. Stopcocks are 2 mm bore. Hose connections on still are size A.