These glass tubes are mainly meant for fun; for with the tubes, a beautiful light phenomenon can be demonstrated. In the tubes are chains, the links of which make contact with each other in different ways. When a charged Leyden jar is connected to these tubes, sparks will jump between the links of the chain. Thus, a magnificent series of sparks is formed. Dischargers with an iron chain like these, were also supplied by Edward Nairne with his medical electrostatic generator (See the Instruments Room, cabinet III, 510). They were also meant for discharging the machine after being used.