SPECTEA OF VAEIOUS GASES. 
887 
band terminating at about 130. Several faint lines intervene between this and another 
broad band at 140, followed by several others less distinctly defined. (Fig, 34.) 
I attempted to obtain the spectra of iodine and bromine by employing a current of 
hydriodic and hydrobromic acid ; but the results were not satisfactory. It is very diffi- 
cult to maintain a steady current of sparks through these gases, and not easy to keep 
up a continuous current of the pure and dry gases, which are immediately decomposed 
by the passage of the electric spark, with extrication of dense fumes of iodine or of 
bromine. 
6 e2 
