Brimstone is easily burned without any extraneous help; indeed the only precaution required is to take care lest the heat produced by the burning sulphur should not volatilize part of it in the unburned state.
To understand the phenomena of the sun, we should reproduce them upon the earth; but this is clearly impossible since they take place at temperatures which volatilize all known substances.
As a class, the metallic bromides are solids at ordinary temperatures, which fuse readily and volatilize on heating.
The majority of the metallic chlorides are solids (stannic chloride, titanic chloride and antimony pentachloride are liquids) which readily volatilize on heating.
Of the simple compounds, only the fluoride is amenable to electrolysis in the fused state, since the chloride begins to volatilize below its melting-point, and the latter is only 5° below its boiling-point.