Vacuum, improved form. Material to be dried is placed in the inner tube, 15.2cm long by 25.4mm I.D. When the liquid in the distilling flask boils, the vapors pass through the drying chamber and heat the inner tube at a constant temperature. The vapors then ascend to the reflux condenser, condense and flow back through the return tube into the boiling flask. Boiling flask is of 250mL capacity and has a 24/40 joint. Flask with interchangeable stopcock has a 40/35 joint. Complete with condenser, drying chamber, desiccant flask, and boiling flask.