Lich ten berg's Figures

If the knob of a Leyden jar or other exited electrode is rubbed over the surface of ebonite, shellac, resin or other non-conducting surface it leaves it electrified in the path of the knob. If fine powder such as flowers of sulphur or lycopodium is dusted over the surface and the exce is blown away, the powder will adhere where the surface was electrified, forming what are called Lich ten berg's Figures, Lycopodium and sulphur show both positive and negative figures, that is to say, lead adheres only to negative figures. If both positive and negative figures are made and the surface is sprinkled with both red lead and flowers of sulphur each picks out its own figure, the sulphur going principally to the positive one. The red lead takes the form of small circular heaps, the sulphur arranges itself in tufts with numerous diverging branches. This indicates the difference in the two electricities. The figures have been described as "a very sensitive electros ope for investigating the distribution of electricity on an insulating surface." (Ganot.)