Where can I find information on the Plurality of Worlds by Bernard le Dobier de Fontielle?
The first thing that will help you in your search is clarifying your question. When you search for the title On the Plurality of Worlds, most search engines will return references to the 1986 work by the philosopher David Lewis, which was a landmark in a certain area of contemporary analytic philosophy focused on possible world semantics.
The book I think you have on mind is Bernard le Bovier de Fontenelle's 1686 work, Conversations on the Plurality of Worlds. The work is a dialogue in which a philosopher and an aristocrat walk in a garden at night watching the stars, and the philosopher explains the heliocentric model of the solar system and speculates about the possibility of life on other worlds. He argues that astronomical observations show rivers and other features on the moon and that microscopes show life to be ubiquitous.
A useful summary of the book can be found at:
You can find English translations of the French original for free on two websites: