Hoffman Voltameter 
suitable for KS4+. Used for demonstrating the decomposition of water, determination of chemical composition by electrolysis and with applications in the evaluation of the electrochemical equivalent of hydrogen. The glass unit has two connected limbs, each of approximately 50ml capacity (graduated 2 - 50ml), integral reservoir tube and funnel-shaped bulb, with a stopcock at the top of each limb. Supplied with electrodes, 2 carbon and 2 platinum. Requires 12V power supply. The apparatus should be set up vertically ideally using a clamp and stand to hold it safely. Connect the terminals to a DC power source. Matches will be required to test for gases. Chemicals required: Water, molar sodium, or potassium sulphate or sulphuric acid. Supplied in neat, well-protected packing case. Hoffman Voltameter.