Pottox & Leonarp—On the Spectra of Barium, Sc. 231 
Barium. 
The salt used was barium chloride; and the most persistent 
lines were situated in the visible part of the spectrum, the 
residuary lines being AX 45542, 4130-9. As metallic barium is 
not easily procured in a state of purity, we were unable to 
determine whether any lines are developed by the metal, but 
not by solutions. 
Plate XVIII.—Spectra 4 and 5 show the spectra with a 
saturated solution, and a 1 per cent. solution of barium respectively ; 
and the dots placed under lines indicate the lines that persist 
with further dilutions. 
Quantitative Spectrum of Barium Chloride. 
pee ar tee | ee ae 
eae aah ; Persistency. | oa ae. ore Persistency. 
252-75 5585°7 10 ¢ 314-30 4283°3 8 6 
258°35 | 5519-4 Aone a2 2075 4166°2 10 9 
256°70 | 5524-8 Ge Ue: 325-45 4130°9 10 @ 
. 276-90 4934-2 10 wy || 330-80 [No. 12, | Gold.] 
278-55 4900-1 [8] « || 336-80 3993°6 Sule 
| 283-83 [No. 9, | Gold. 344-25 3910°1 6 6 
287-32 4726°6 ie) ve 345-10 [No. 13, | Gold.] 
289°20 4691°7 [3] « 345-95 3892-0 10 ¥ 
293°80 4673°7 [3] o 377°50 [No. 14, | Silver. ] 
296°85 4554-2 10 387-95 3501-3 Beeb 
298°63 4525-2 10 x 403°55 [No. 15, | Silver.] 
299-80 4506-1 6 oo 406-90 3357-0 [4] o 
| 300-85 [No. 10, | Gold.] 50620 [No. 20, | Gold. ] 
304-45 4439-1 8 « || 519-60 2771°5 8 ¢ 
306-25 4402°7 8 ao || 555-45 [No. 23, | Gold.] 
309-70 4350-5 6 oo 557-40 2634:9 8 
312-10 [No. 11, | Gold.] 
| 
