A Glass rod, stirring rod or stir rod is a piece of laboratory equipment used to mix chemicals and liquids for laboratory purposes. They are usually made of solid glass, about the thickness and slightly longer than a drinking straw, with rounded ends.Click to see full answer. Furthermore, what is the purpose of a stirring rod?Long, thin stirring rods are an essential piece of laboratory equipment used to mix chemicals and liquids for reaction purposes. Stirring rods are fabricated from glass, with steel cores, or in solid plastic, and they are chemically resistant, inert, and non-abrasive.Furthermore, why is glass rod used in filtration? Glass rods are used when pouring liquids in order to avoid spills. When a glass rod is laid against the pouring edge of a beaker, it causes the liquid inside to flow along the rod and down into the receiving vessel instead of splashing over the lip. Secondly, why is it important to use a glass stir rod instead of a metal one? Glass rods are also used to spread liquid substances on a solid surface. It is preferable to a metal rod because glass is not a good conductor of heat and metal is. Metal has free electrons. Therefore, in metals, conduction takes place due to the atomic vibration and the drift of the free electrons.Why is it called a rubber policeman?Several correspon- dents educated in Great Britain and Australia insisted that their Science Masters had told them that the rubber policeman received its name because it resembled the helmets used by British “Bobbies.” Of course it looks nothing at all like a policeman’s helmet.