When Montresor says he was so glad to see Fortunato that “[He] thought [he] should never have done wringing his hand,” Poe is using what kind of literary device?
In "The Cask of Amontillado," by Edgar Allen Poe, the author is using hyperbole in the quote, "I was so pleased to see him, that I thought I should never have done wringing his hand."
Poe is essentially saying, "I was so happy to see him that I though I would just keep shaking his hand forever!"
Hyperbole is the use of exaggeration to make a point. The exaggeration here is that he could shake someone's hand forever, when it probably just ended up being a normal handshake.
Poe is making the point that Montresor is incredibly glad to see Fortunato. This is not because they are friends, or love to spend time with one another, but because Montresor is plotting revenge upon Fortunato and is glad to happen upon him just as he is ready to begin to enact his revenge plan.