Timeline of chemistry lists important works, discoveries, ideas, inventions, and experiments that significantly changed mankind's understanding of the composition of matter and of the interactions thereof, the modern science known as chemistry. The history of chemistry in its modern form is often considered to begin with the English scientist Robert Boyle, though its roots can be traced back to the earliest recorded history. Early ideas that later became incorporated into the modern science of chemistry come from two main sources. Natural philosophers such as Aristotle and Democritus used deductive reasoning in an attempt to explain the behavior of the world around them. Alchemists were people who used experimental techniques in an attempt to extend the life or perform material conversi...more >>ons, such as turning base metals into gold. In the 17th century, a synthesis of the ideas of these two disciplines, that is the deductive and the experimental, leads to the development of a process of thinking known as the scientific method. With the introduction of the scientific method, the modern science of chemistry was born.