XXXIV. On the photographic transparency of various bodies, and on the photographic effects of metallic and other spectra obtained by means of the electric spark

Abstract

1. At the Meeting of the British Association held in Manchester last autumn, I exhi­bited some photographs of spectra from the electric spark obtained between wires of different metals by means of an induction-coil. Upon this occasion a hollow prism tilled with bisulphide of carbon was employed, because, owing to its great dispersive power, it furnished spectra in which the lines under examination were more widely separated and exhibited with greater distinctness than by any other medium in ordinary use. Plate XXXIX. fig. 30 exhibits a copy of the photograph of the solar spectrum obtained by means of a hollow glass prism filled with bisulphide of carbon, contrasted with the spectrum obtained through the same prism simultaneously from the spark between copper terminals of the secondary coil in the induction apparatus. In this, and in all the subsequent figures, the less refrangible end of the spectrum is upon the left-hand side of the Plate.