216 



Scientific Proceedings, Royal Dublin Society. 



With tlie metal many more lines are seen than with the chloride, and 

 when a condenser is introduced there is a considerable change in the intensity 

 of many of the lines, and in the case of the chloride the chlorine lines develop. 

 In the spectrum of the chloride some of the lines of cadmium show in 

 addition to those of the element. 



Principal Lines of Antimony. 



Aluminium. 



The metal will not give a spectrum in the vacuum tube, but the anhydrous 

 chloride gives a beautiful luminescence, and the characteristic pairs of 

 aluminium show well, both with and without the condenser. Without a 

 condenser, and when much vapour is present in the tube, aluminium cliloride 

 gives a beautiful band from \ 2750 to X 2610, and a weaker band from \ 2610 

 to X 2590, both having their heads at the more refrangible side, and degrading 



