A. Glass is a non-conductor; and, as the bottom of the glass (from the warmth of the hot stove) expands, before the sides are heated, the two parts separate the one from the other.
CHAPTER XI.
2.—LIQUEFACTION.
3.—VAPORIZATION.
Q. What is meant by liquefaction?
A. The state of being melted; as ice is melted by the heat of the sun.
Q. Why is ice melted by the heat of the sun?
A. The heat of the sun (entering the solid ice) forces its particles asunder, till their attraction of cohesion is sufficiently overcome, to convert the solid ice into liquid. (See p. [112].)
Q. Why are metals melted by the heat of fire?
A. The heat of the fire (entering the solid metal) forces its particles asunder, till their attraction of cohesion is sufficiently overcome, to convert the solid metal to a liquid.