Geissler Tube

Geissler Tube. Colorless, transparent brown, transparent blue, and opaque white glasses, metal; lampworked. Glass tube with two ovoid ends, each containing a metal rod. One end has small pulled glass attachment. Tube between ends manipulated into flattened spiral shape made of brown glass. Spiral shape is flanked by two bulbous shapes: one half blue and half brown; one half white and half brown.