Geissler's Tubes

Device constructed by H. Gei ler of Bonn (1814-1879) for illustrating the luminous effects of the electric discharge. They consist of tubes of gla worked into various fanciful shapes and sometimes filled with rarefied gases and fluorescent solutions of different kinds. The gla itself is often made fluorescent by the presence of uranium or sulphate of quinine, and the discharge from a powerful induction coil is Gei ler's Tubes. capable of producing various brilliant effects. Prof. Plücker of Bonn contrived a set of tubes containing the various gases, but especially adapted for spectroscope work. The middle portion of the tube is of capillary bore, and the discharge through this narrow channel renders the gas far more luminous than in the wider parts of the tube.