CHAPTER II.. The Laws of Changes Occasioned by Heat.

THE LAWS OF CHANGES OCCASIONED BY HEAT.

Sect. 1.--Expansion by Heat.--The Law of Dalton and Gay-Lussac for Gases.

ALMOST all bodies expand by heat; solids, as metals, in a small degree; fluids, as water, oil, alcohol, mercury, in a greater degree. This was one of the facts first examined by those who studied the nature of heat, because this property was used for the measure of heat. In the Philosophy of the Inductive Sciences, Book iv., Chap. iv., I have stated that secondary qualities, such as Heat, must be measured by their effects: and in Sect. 4 of that