Q. Why is ether better for this purpose than water?
A. Because it requires less heat to convert it into vapour; and therefore it evaporates much more quickly.
(Ether is converted into steam with 104 degs. of heat, but water requires 212 degs. of heat to convert it into steam.)
Q. Why does ether very greatly relieve a scald or burn?
A. Because it evaporates very rapidly; and (while it is converted into vapour) carries off the heat of the burn.
Q. Why do we feel so cold when we have wet feet or clothes?
A. As the wet of our shoes or clothes evaporates, it keeps absorbing heat from the body, which makes it feel cold.
Q. Why do wet feet or clothes give us “cold?”
A. Because the evaporation absorbs heat from the body so abundantly, that it is lowered below its natural standard; and therefore health is injured.
Q. Why is it dangerous to sleep in a damp bed?