FLAME SPECTRA AT HIGH TEMPERATURES. 
183 
Phosphorus Pentoxide. 
A strong continuous spectrum extends from near the yellow sodium line to about 
X 4090, A number of lines were observed many of which were identified with those 
of iron at wave-lengths 3888-2, 3860-5, 3749-4, 3747-6, 3736-9, 3733-5, 3722-8, 
3720-2, 3705 - 5 , 3440-2, and 3431-1, The following lines, all very faint, were not 
identified with any other substance, and it is probable that they are Indications of a 
feeble band spectrum. 
Ivory scale-numbei’s. 
X. 
168-5 
3279 
169-2 
3274 
169-7 
3271 
170-05 
3268 
171-6 
3255 
172-9 
3245 
Arsenic. 
This element gave a faint nebulous line at 168-4 or X 3280, which approximates 
the first line in the PoO^ spectrum. 
