"Conversations on chemistry" by Jane Marcet is an early effort in popular chemistry writing, first published in 1805. It has sold nearly 160,000 copies over the years and influenced many 19th century scientists.

The Royal Society of Chemistry has made the 10th edition from 1825 available online as pdf files here:

http://www.rsc.org/Library/LICHelp/HistoricalChemistry/Conversations/

and selected parts have also been reprinted as a book under the title "Chemistry in the schoolroom: 1806"

A snippet of the preface: