150 years ago John Dalton
formulated the idea that the world around us is made up of large numbers of identical very small particles called molecules,
and that the many types of different kinds of molecules are simply differently arranged groups of atoms. It is this idea of
the molecule that lies at the heart of chemistry.
The relative masses of compounds and elements were studied extensively in the 18th century.
John Dalton recognized a pattern in collected measurements and created a set of empirical laws which we now call the atomic
theory of matter.
The understanding of the nature of matter as molecules was first set down by John Dalton . In the course
of his studies and teaching he developed the ideas which led to his formulation of the atomic theory of matter in 1805.
Quantitative chemical measurements had lead to several empirical laws. Dalton
was the first to come up with a theory that attempted to explain the empirical laws. It was to explain these empirical laws
that he developed the atomic theory of matter.
