Although there is verbal irony throughout Edgar Allan Poe's short story, "The Cask of Amontillado," examples excluding the antagonist Fortunato are quite limited. As Montressor leads his intended victim deeper into the catacombs, he decides to ply Fortunato with more wine.
Here I knocked off the neck of a bottle which I drew from a long row of its fellows that lay upon the mould.
The phrasing of "knocked off" and "fellows that lay" are ironic in that soon Fortunato will also be killed by Montressor and rest upon the mouldy floor. Montressor drinks also and begins to feel the effect of the drink.
My own fancy grew warm with the Medoc.
It is ironic that Montressor's cold heart is now being warmed by the same ingredient that will seal Fortunato's fate. Similarly, in the example below, Montressor's heartlessness shows life:
My heart grew sick; it was the dampness of the catacombs that made it so.
However, it is not the evil nature of the murder that sickens his heart or pity that awakens its sympathies; instead, it is the wet nature of the catacombs.