The history of chemistry is long and convoluted. It begins with the discovery of fire; then metallurgy which allowed purification of metals and the making of alloys, followed by attempts to explain the nature of matter and its transformations through the protoscience of alchemy. Chemistry begins to emerge when the distinction is made between chemistry and alchemy by Robert Boyle in his work The Sceptical Chymist (1661). Chemistry then becomes a full-fledged science when Antoine Lavoisier develops his laws of Conservation of mass, which demands careful measurements and quantitative observations of chemical phenomena. So, while both alchemy and chemistry are concerned with the nature of matter and its transformations, it is only the chemists who apply the scientific method.The history of chemistry is intertwined with the history of thermodynamics, especially through the work of Willard Gibbs.