what did john dalton do at 12 that he carried out through his life?

what was his ides on schemicals react?
which theory did he come up with?

Since this is not my area of expertise, I searched Google under the key words "John Dalton" to get these possible sources:

https://www.google.com/search?client=safari&rls=en&q=John+Dalton&ie=UTF-8&oe=UTF-8&gws_rd=ssl

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.

http://www.hackcollege.com/blog/2011/11/23/infographic-get-more-out-of-google.html