Band and Line Spectra of the same Metallic Elements. 125 
between \ 5100 and X4700 disappears at the same time as the sharp composite 
bands between \ 4279 and » 4000; likewise the strong diffuse composite band 
between \ 5800 and 5100 disappears along with the strong sharp composite band 
between A 4650 and 4279. The line \ 3274 persists after the bands have 
disappeared. 
Quantity of 
Copper. 
Or GR. iH Bands. 
1 portion. Between) 5800 and 5100, a diffuse composite band, fairly strong. 
Between \ 5100 and 4700, a diffuse composite band, feeble. 
Between \ 4650 and 4279, a sharp composite band, rather strong. 
Between \ 4279 and 4000, a sharp composite band, feeble. 
Line )\ 3274, strong. 
0-1 gr. in 10 The whole spectrum is more intense than the foregoing, and 
portions of | there are five bands instead of four. This is accounted for by 
OO gar there being the same quantity of copper in the flame, but intro- 
duced in ten small proportions, which increases the exposure of 
the photographic plate to an extent which is at least five times as 
long a period as that occupied in the previous case. 
Bands. 
Diffuse composite between d 5800 and 5100, strong. 
Diffuse composite between \ 5100 and 4700, rather strong. 
Sharp composite between 4 4650 and 4279, strong. 
A sharp composite band between \ 4279 and 4000, rather strong. 
A sharp composite band between » 4000 and 3800, very feeble. 
Line \ 3274, very strong. 
0-01 gr. in Two bands. 
1 portion. Diffuse composite band between d 5800 and 5100, very feeble. 
Sharp composite band between 44650 and 4279, very feeble. 
These are apparently near the point of extinction. 
Line \ 3274, feeble. 
0-01 gr. in 10 This experiment and the previous one are comparable with 
portions 0-1 gr. in 1 portion, and in 10 portions respectively. 
Bands. 
A diffuse composite band between d 5800 and 5100, feeble. 
A diffuse composite band between \ 5100 and 4700, very faint. 
A sharp composite band between \ 4650 and 4279, strong. 
Line ) 8274, strong. 
Norre.—The spectrum 0:1 gr. in 1 portion has four bands—the two sharp 
composite and two diffuse composite corresponding; but the same quantity in 
TRANS. ROY, DUB, SOC., VOL. IX., PART VII. xX 
