Slow conduction of manganate ions

This experiment is an old favourite from the Nuffield course. The bulldog clips are connected to about 30V. The filter paper is soaked in ammonia solution and a crystal of potassium manganate (vii) is put onto the filter paper. The top clip was positive. The negative manganate ions are coloured (manganese is a transition metal so has coloured compounds). The coloured ions are clearly attracted to the positive. They travel slowly - 5mm in 1 minute. This is in contrast to the seemingly instant movement of electricity when you flick a switch. In reality the charge carriers move haphazardly, crashing into things. They seem to go slowly and we can calculate their "drift velocity". Electricity seems instantaneous because they all move together so there is always movement in any given part of the circuit.