YTTRIUM OXIDES. 



115 



Beryllium Oxide (BeO); Silicon Oxide (Si0 2 ); Vanadium Oxide (V 2 6 ). 

 (Curve a=BeO; b and c = Si0 2 ; fig. 82.) 



The beryllium-oxide emission spectrum is smooth, with two wide 

 maxima at 3.5 and 5 /*, respectively. The temperature was such that a 

 faint red showed through the interstices of the layer of white oxide. 



The silicon-dioxide (quartz, French flint) curve shows bands at 2.2, 

 2 -&3> 3-7> 4-4> and 5.3 /<, which coincide with the absorption bands (see 

 Carnegie Publication No. 65, p. 21). For curve c the layer of silica was 1.4 

 mm. For curve b (thinner layer) the surface temperature was about 8oo. 



3 4 5 6 



Fig. 83. Yttrium oxide. 



The vanadium oxide in the preliminary examination showed no emis- 

 sion bands. The substance is a black powder, which melted at a low red 

 heat, and no further examination was made into its emission spectrum, 

 which was similar to that of carbon. Curve d, fig. 82, shows the emission 

 band of pure feldspar placed on the heater. 



