Conductivity of solution with free ions

A circuit with a 9 volts batter and a 9 V light bulb is constructed with part of the circuit running through normal tap water. The bulb doesn’t light. As table salt is added to the water and the table salt ions dissociate and makes the salt water able to transmit current the light bulb glows brighter and brighter thus showing how charges can move in a solution and make a substance conductive that was previously non-conductive.