We might at first suppose that the sun was really an intensely heated body radiating out its heat as does white-hot iron, but this explanation cannot be admitted, for there is no historical evidence that the sun is growing colder.
In de Lambilly's process air and steam is led over white-hot coke, and carbon dioxide or monoxide removed from the escaping gases according as ammonium formate or carbonate is wanted.
Then, by the use of another piece of platinum as anode, mercury is electrolytically deposited upon the platinum, which may also be amalgamated by making it white hot in a Bunsen flame and plunging it in mercury.
Salet observed that iodine gives a spectrum of bright bands when in contact with a platinum spiral made white hot by an electric current, and J.
When now a small bead of a salt of sodium or lithium is placed in the flame the spectrum of the white hot platinum is traversed by the dark absorption of the D lines.