A Manchester Quaker, Dalton formulated the first atomic theory that could be tested; this transformed the later study of chemistry.
Citation:
Editors. "Atomic theory formulated by John Dalton".
The Literary Encyclopedia. First published 01 February 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=4638, accessed 19 June 2013.]