612 



Scientific Proceedings, Royal Dublin Society. 



they are chiefly confined to the green region. The introduction of self- 

 induction causes the lines to become sharper and more distinct, and in 

 some cases they are intensified, which is the opposite effect to that produced 

 with oxygen and nitrogen. 



The rays between A 3533 and A 3230 are absorbed ; no lines show in 

 this region when gold electrodes are used. With carbon electrodes the 

 absorption is not so extensive. 



Three fairly strong lines A 5140'0, A 5099-0, and A 5072'8 appear with 

 self-induction when both gold and carbon electrodes are used; the line 

 A 5140"0 disappears without self-induction, but the others remain. These 

 lines must be due to chlorine, but no record of their measurements can 

 be found. Some lines of chlorine between A 6093 and A 5580, which show 

 using gold electrodes, are not seen with carbon. The clearest and most 

 complete spectrum of chlorine is obtained by using gold electrodes with 

 self-induction present. All these chlorine lines showed in the spectrum 

 of hydrochloric acid together with the lines of hydrogen. 



Principal Lines of Chlorine. 



