"And as the richest Diamond cannot shoot forth its Lustre, wanting the Lapidary's Skill; so will the latent Virtues of the noblest Mind be bury'd in Obscurity if not call'd forth by Precept, and the Rules of good Manners."
An Index to Mankind: or Maxims Selected from the Wits of all Nations 
An Index to Mankind: or Maxims Selected from the Wits of all Nations (Dublin: James Hoey, 1765). &lt;<a href="http://books.google.com/books?id=5JUDAAAAQAAJ">Link to Google Books</a>&gt;