Band and Line Spectra of the same Metallic Elements. 137 
The Characteristic Flame-Spectra of the Elements. 
Group Sus-Grovp 
Vig 7 bale K, Rb, Cs, Na, Cu, Ag, Au, 1s 
Line spectra with greatest facility. Banded spectra, with ultimate lines 
in Cu and Ag. 
OL, 130, Ca, Sr, Ba, Me, Zn, Cd, JO, 
Band spectra, with limited line Band spectra, with lines increasing in 
spectra. number with atomic weight. 
OUT, 383, Se, Yt, La, Al, Ga, In, 701, IDL, 
No spectra. Band spectra. Lines chiefly ; bands ill-defined. 
IN, Of a, Zr, Ce, Si, Ge, Sn, Pb, IV. 
No spectra in this group. Band spectra, with few lines in 
Ge and Pb. 
Wo WW VA Nb, Di, Ta, Qe, AS) Sb, Bi, AG 
No spectra in this group. Band spectra. 
Wik  @, Cr, Wl, Ws Ur, S, (Se), Te, Val, 
Chiefly No spectra. Band spectra. Se not examined. 
lines. 
Mn, Bands very numerous and strong, with the ultimate lines 
18@, Ii, Co, y Line spectra, with bands of diffuse and indistinct character in the iron group. The lines 
Pd, ip, }} preponderating largely over the bands in both groups. 
The following facts are to be observed :— 
Ist. The facility with which the alkali metals yield line spectra. 
2nd. The facility with which the alkaline earth metals yield band spectra 
of a special character, and but few lines. 
3rd. That the elements in groups* III, IV, V, and VI exhibited scarcely 
any but continuous spectra in the flame, nevertheless the corre- 
sponding are and spark spectra are remarkable for their complexity. 
4th. Each of the sub-groups contains, as a rule, three elements, which 
yield characteristic flame spectra, with either lines or bands 
preponderating. 
* It is worthy of remark that the spectra of scandium and yttrium obtained with the condensed spark 
are similar in character, in that each element displays a beautiful group of bands. These are similar to 
the bands of beryllium and aluminium obtained with difficulty in the flame. Such bands are quite 
exceptional in spectra obtained from a powerful spark. The scandium and yttrium spectra display also 
at the same time a large number of lines. 
TRANS. ROY. DUB. SOC., VOL. IX., PART VII. Z 
