Remove the plungers from two 10 mL syringes and bore out the needle port with something sharp (knife, thin pliers, etc.). Remove material gradually, rotating the piece to ensure a circular cut. When the hole is just big enough, force through a graphite battery electrode so 0.5-1 cm remains on the outside. Twist the electrode during insertion to prevent it from snapping. The gap should be air-tight, but if the cut was too big or irregular you can seal the holes with super glue. Attach wires to the exposed part of the electrodes. To use the cell, fill the tubes with your electrolyte solution and place them wire end up in the cut off bottom of a large water bottle, also filled with elec- trolyte solution. Attach the wires to a power supply (three or more 1.5 V dry cell batteries in series, a 6 V motorcycle battery, or a 12 V car battery) to start electrolysis. The volume of gas produced at each electrode may be measured by the gradations on the syringes, and other products (copper metal plating, iodine in solution) may be clearly observed