 Dyssalation is an important technique for separating substances. In a simple distillation setup that we have here, we have a solution of methylene blue in methanol. The methylene blue is a non-volatile compound. The methanol has a fairly low boiling point. As we heat the solution in the distilling flask with an electric heating mantle, the methanol reaches its boiling point and converts to a vapor. The vapor from the methanol travels up to the still head and condenses on the thermometer. Since the thermometer is in the interface between the liquid and the vapor, the thermometer reads the boiling point of the methanol, which is 65 degrees Celsius. The vapor then travels over into the condenser and is cooled by a stream of water and condenses from the vapor back to the liquid. At the end of the distillation, we have pure, colorless methanol in the receiving flask.