With charges flowing towards the left inside the discharge tube, maybe a flow of water around the tube and a ring of light dust particles around the tube in the direction of the \(g\) field can be seen. A tiny drop of ink might indicate the flow direction of water more clearly.
Water smear and dust tend to stay on the tube when it is on, but these phenomena are attributed to static electricity and not the presence of a \(g\) field proposed here.
Maybe...
