Elements of chemistry : including the applications of the science in the arts . nium does not conduct electricity, and its metallic characters arenot constant, it is better classed with the non-metallic bodies. Its powder is of adeep red colour. By heat it is softened, becoming semifluid at 392°, and fusingcompletely at 482°. It remains a long time soft on cooling, and may then be drawnout like sealing-wax into thin and very flexible threads, which are grey and exhibit ametallic lustre by reflected light, but are transparent and of a ruby red colour bytransmitted light. It boils about 1292°, a
Elements of chemistry : including the applications of the science in the arts . nium does not conduct electricity, and its metallic characters arenot constant, it is better classed with the non-metallic bodies. Its powder is of adeep red colour. By heat it is softened, becoming semifluid at 392°, and fusingcompletely at 482°. It remains a long time soft on cooling, and may then be drawnout like sealing-wax into thin and very flexible threads, which are grey and exhibit ametallic lustre by reflected light, but are transparent and of a ruby red colour bytransmitted light. It boils about 1292°, and gives a vapour of a yellow colour, lessintense than that of sulphur, but more so than that of chlorine. The density of thisvapour has not been ascertained. When heated to the degree of ignition, seleniumemits a po^rful odour, suggesting that of decaying horse-radish, by means of whichthe smallest trace of this element may be detected in minerals, when heated beforethe blow-pipe. The odour was first ascribed to a gaseous oxide of selenium, but it 312 SELENIUM. Fig. is found by M. Sacc that selenium heated in perfectly dry air is inodorous, ami theodour is now referred to the production of a minute quantity of hydroselenic acid. Selenium combines in two proportions with oxygen, forming selenious acid, whichcorresponds with sulphurous acid, and selenie acid corresponding with sulphuricacid. Sehnious acid; eq. or 691; Se02. — Selenium does not burn in air, but when strorlgly heated in the bend of aglass tube a b c, (fig. 145), with a cur-rent of oxygen passing over it, seleniumtakes fire and burns with a flame, whiteat the base, and of a bluish green at thepoint and edges, but not strongly lumin-ous ; selenious acid at the same time con-denses in the upper part of the tube as awhite sublimate, in long quadrilateralneedles. Its vapour has the colour ofchlorine. The same acid is the onlyproduct of the action of nitric or nitro-muriatic acid upon selenium, and is o
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