The high viscosity of sulphur is due to the ring type structure or polymerization of sulphur. Also in liquid sulphur, H2S is the reason which affects its viscosity significantly.
To get the viscosity of liquid sulphur closer to pure sulphur, It is necessary to get it degassed in a sulphur tank based on its source. The H2S tends to make the liquid sulphur less viscous. It can be understand well by quenching the sealed capsules. For some days, the polymer rubbery state of sulphur persists and finally decomposes into the sulphur powder.
The equipment required for the demonstration-
At first, put about 2 inches sulphur into the test tube. Heat the tube slowly. Tip tube to show the viscosity of melted sulphur and continue to heat. Viscosity drops with the increasing heat of liquid. Keep showing the viscosity of sulphur while continue heating the tube over burner. There will be some points where sulphur would become molasses. Viscosity starts dropping as heat is applied to it. This change in viscosity can be seen by cooling the tube and molasses reappear. After reheating the sulphur above its viscosity state, pour it into the water in beaker. It will solidify into rubbery material and become plastic sulphur, yellow, rhombic form.
Following are the different stats it passes-