Ok this could be a very rare text, not sure but it appears to be a defense of Socrates against the accusation of homosexuality by Johann Mathias Gesner (1691-1761) Its importance can be ascertained as the Latin text is online on the University of Göttingen website. I can not find any examples for sale currently but I have not done an exhaustive search. As for value you would need to do a auction record search , but world cat only shows 17 antiquarian volumes in various institutions so it is likely a library may want to acquire this book so that might really pump the value. This was a very good find , well done.