Chemistry: A Volatile History Chemistry: A Volatile History Chemistry: A Volatile History is a 2010 BBC documentary on the history of chemistry presented by Jim Al-Khalili. It was nominated for the 2010 British Academy Television Awards in the category Specialist Factual. Only in the last 200 years have we known what an element is – a substance that cannot be broken down further by chemical reaction. The Ancient Greeks, with no way of breaking open substances, could only base their ideas of the elements on what they could see: Earth, Fire, Water and Air. In the 16th century alchemists were busy trying to turn
Principle (chemistry) Principle (chemistry) Principles - historical concept of the constituents of a substance, specifically those that produce a certain quality or effect in the substance, such as a "bitter principle", which is any one of the numerous compounds having a bitter taste. The idea of chemical principles developed out of the classical elements. Paracelsus identified the "tria prima" as principles in his approach to medicine. Georg Ernst Stahl published "Philosophical Principles of Universal Chemistry" in 1730 as an early effort to distinguish between mixtures and compounds. He writes, "the "simple" are "Principles", or the first material causes of "Mixts";..." To define