Replacement glass parts for Hoffman electrolysis apparatus. Included is the main glass apparatus only (stand and electrodes are not included). The apparatus consists of two vertical 50ml graduated glass tubes, with stopcocks at the top. The vertical tubes are joined by a bridging tube to a central reservoir. Each vertical tube is designed to accommodate an economy platinum electrode that extends through a rubber stopper, so that only the platinum electrode comes in contact with the electrolyte. Comes complete with a padded storage box to help prevent glass breakage.