Connect the white end of the wire to a paper clip in the solution. Connect the orange end of a second wire from the longer leg of the LED diode to a second paper clip on the opposite end (red). Connect the green wire end to the positive terminal of the battery holder (look for the " sign in the battery holder) and the yellow end to the shorter leg of the LED diode. Make sure the two legs of the LED diode are not touching each other. Insert two D-cell batteries into the battery holders Test the circuit by touching the paper clips together. The LED diode should emit a red light if the circuit is connected properly . When placing the two paper clips into a solution, make sure the two paper clips are not touching each other