<P> The history of chemistry represents a time span from ancient history to the present . By 1000 BC, civilizations used technologies that would eventually form the basis of the various branches of chemistry . Examples include extracting metals from ores, making pottery and glazes, fermenting beer and wine, extracting chemicals from plants for medicine and perfume, rendering fat into soap, making glass, and making alloys like bronze . </P> <P> The protoscience of chemistry, alchemy, was unsuccessful in explaining the nature of matter and its transformations . However, by performing experiments and recording the results, alchemists set the stage for modern chemistry . The distinction began to emerge when a clear differentiation was made between chemistry and alchemy by Robert Boyle in his work The Sceptical Chymist (1661). While both alchemy and chemistry are concerned with matter and its transformations, chemists are seen as applying scientific method to their work . </P> <P> Chemistry is considered to have become an established science with the work of Antoine Lavoisier, who developed a law of conservation of mass that demanded careful measurement and quantitative observations of chemical phenomena . The history of chemistry is intertwined with the history of thermodynamics, especially through the work of Willard Gibbs . </P>

When did chemistry replace alchemy as a science