John Dalton (1766–1844) was born into a modest Quaker family in Cumberland, England, and earned his living for most of his life as a teacher and public lecturer. After teaching 10 years at a Quaker boarding school in Kendal, he moved on to a teaching position in the burgeoning city of Manchester.
Dalton joined the Manchester Literary and Philosophical Society, which proved to be a stimulating and intellectual environment with laboratory facilities. The first paper he delivered before the society was on colour blindness, which he himself suffered from.
Although his theories would eventually lose credence before his death in 1844, he was widely respected for the thorough scientific precision with which he conducted his research. Dalton was keenly interested with meteorology and kept daily weather records from 1787 until his death, his first book was Meteorological Observations (1793), and he read a series of papers on meteorological topics before the Literary and Philosophical Society between 1799 and 1801.
This fascination with the weather would ultimately influence his views on Atomism, and he is widely regarded as the leading pioneer of his generation in the field and creator of Atomic Theory. His investigations were to revolutionise the way in which we viewed the Atomic composition of all things, in particular gases which he theorized were comprised of separate particles of varying densities and weights.
As a Quaker, Dalton led a modest existence, although he received many honours later in life, including a statue which still stands in Manchester Town Hall today. He has had several terms coined in his memory, most notably in the referring to colour blindness as Daltonism (indeed the French for colour blindness is Daltonien). In Manchester more than 40,000 people marched in his funeral procession.