Irony - It's like rain on your wedding day, it's a free ride when you've already paid.
Seriously though, Jonathan Swift uses irony throughout his whole essay "A Modest Proposal". I would be lying if I said the though of eating babies has never crossed my mind. Swift's ideas, if they were taken seriously would have actually aided the dire economic situation in Ireland at the time. A great example of irony that stood out to me is at the bottom of paragraph 17- "it is not improbable that some scrupulous people might be apt to censure such a practice (although indeed very unjustly)..." What Swift is referring to here is people speaking out about the murdering and cannibalism of 12-14 year old boys and girls. The irony comes in as the word "unjustly". Swift is saying that it is wrong for anyone to be against this practice, even if the country is starving. I think it is safe to say that this is irony and should not be taken seriously.
