222 Scientific Proceedings, Royal Dublin Society. 
Auuminium. (Plate XIII.) 
Spectra 1, 2, 3, and 4 show the lines of the metal, and a 
strong solution as in the previous plate. There is a strong 
aluminium line at ’ 3587:0, practically coincident with gold line 
No. 14 (A 3586°5), and in consequence it cannot be followed in 
the dilution spectra. Quite a number of lines show strongly 
with the metal, but only very faintly, or not at all, with solutions. 
Of those the following belong to aluminium :— 
4663°1 107 3064:°4 Sr 
4530°9 Or 30573 Sr 
4511-9 Or 3004°8 Sz 
4479-4 67 3050°2 87 
3066°3 Sr 
The rest between gold lines 22 and 24 belong to iron, and 
come from the small traces of iron in metallic aluminium, and 
they correspond with the most persistent lines of the iron solutions. 
Spectra 5, 6, 7, and 8 show the progressive disappearance of the 
aluminium lines on dilution. 
QUANTITATIVE SpEcTRUM oF ALUMINIUM CHLORIDE. 
Intensity Intensity 
Wave-length. and Wave-length. and 
Persistenvy. Persistency. 
30961°7 9w 2816°4 10x 
3944-2 Iw —21—22 - 
ee 2660-5 5o 
3587-0 10 2652°6 5 
——- 14-17 -——— — 23-24 
3092°8 oy 2575-5 7 
3082°3 oY 2068°1 7p 
Se) 20 5 a a 
