A. The principal ingredient of water. It is well known in the form of common coal gas: it burns so readily that it used to be called “inflammable air.”[10]
[10] To make hydrogen gas, see p. [34>].
Q. Why does a candle burn when lighted?
A. The heat of the lighted wick decomposes the tallow into its elementary parts of carbon and hydrogen; and the hydrogen of the tallow, combining with the oxygen of the air, produces flame.
Q. Why is the flame of a candle hot?
A. 1st—Because the flame liberates latent heat from the air and tallow: and
2ndly—It throws into rapid motion the atoms of matter.
Q. How is latent heat liberated by the flame of a candle?
A. When the hydrogen of the tallow and oxygen of the air combine, they condense into water; and much of their latent heat is squeezed out.
Q. How are the atoms of matter disturbed by the flame of a candle?