360 



Sdientific Proceedings, Royal Dublin Society. 



Chromium. 



Oliromyl chloride was used, and gave the spectrum with great ease, 

 showing all the principal lines of the spark spectrum of the metal ; no 

 bands were seen. The condenser made little or no difference. 



Principal Lines of Chromium. 



NlCKEI, 



Nickel chloride gis'es its spectrum with great ease in the vacuum tube, 

 all the principal lines of the spark spectrum of the metal showing both witli 

 and without the condenser. Bauds are not very prominent. 



