2o8 



Scientific Proceedings, Royal Dublin Society. 



Manganbse. 



Manganous chloride gave a veiy brilliant luminescence in the tube, 

 and the photograph showed all the lines of the spark spectrum of metallic 

 manganese with very strong bands in the visible part of the spectrum 

 from X 3980 to X 3520, and the introduction of the Leyden jar into 

 the secondary circuit made very little difference to either the lines or the 

 bands. It was remarkable that three lines that are quite weak or only 

 of medium strength in the spark spectrum of the element showed very 

 strongly in the vacuum tube. I noticed the same three lines present as 

 impurities in the spectra obtained from potassium chloride, barium chloride, 

 and metallic lithium, though no other lines of manganese showed ; the lines 

 are X 2801-3, X 2798-5, X 2795-3, and their origin should be further 

 investigated. They are certainly not the ultimate lines of manganese in 

 the spark spectrum, these being marked w on the table. 



Principal Lines of Manganese. 



