In this image, drawn by James Gillray in 1792, John Bull--who represents both England and King George III--alongside the Queen as they advise their daughters to boycott putting sugar in their tea, telling them it's "O delicious! delicious!" even without it. Leading up to the Romantic Era, people (including Samuel Coleridge and Robert Southey) refused to eat anything that was a product of slavery, and that included sugar since it came in from slaves in the West Indies. This practice was taken up by thousands of people in order to protest slavery, and it was particularly common among women, seeing as how those were the people who were more likely to hold afternoon tea. It was a highly successful protest; sugar sales decreased dramatically.
Upon closer examination of the cartoon, it's interesting to note the faces of the daughters in this cartoon. None of them look very eager to give up sugar, but some of them look resigned to it while others seem almost to refuse to boycott. The two daughters closest to the front seem to have their eyes on the empty spot on the small table where the sugar would normally go, one of them looking more reluctant and the other looking with more of a wistful stare. It's interesing to know that around 300,000 people gave up sugar for the Abolitionist movement; the estiamted population in England at that time was around 6 million people. Even though only about five percent of the country gave up sugar, that alone dropped sugar sales by at least half, but it sometimes went as low as one third its normal.