Slavery in art

While digging a bit deeper into a reference by Hochschild to J.M.W Turner's painting "Slavers Throwing Overboard the Dead and Dying. Typhon Coming On" (above), I was fascinated to discover that Emily Bronte's Wuthering Heights is believed by some to be filled with references to the slave trade. I had never even suspected such a link. Heathcliff comes from Liverpool and is persistently referred to as having a "swarthy" complexion. Is he a child of the slave trade? But, more interesting, did he himself become complicit in the trade during the time frame of the Novel? The author and academic Marina Warner says:

"...just before she died Angela Carter told me she was going to write an introduction to Wuthering Heights. She had a very interesting theory about what it was that Heathcliff had been up to. If you remember, Heathcliff goes away and comes back having made a fortune, and it takes place during this period we are talking about. One of the few things we know about Heathcliff is that he is found as a child in the Liverpool docks. Angela's theory was that, hidden in rather the same way as Turner approaches the story of the slave ship, and at the same time hides it under the paint, the Brontës similarly knew about slaving, they knew about the trade, they hinted at it in the Liverpool origin of Heathcliff, and this unexplained fortune that he brings back makes him feel damned. He says "I have sold my soul." Angela's theory was that he had sold his soul, that he was a black child, or half-black child – Brontë insistently calls him 'swarthy' – who had returned to Africa as a factor working for the British slavers, and done the trade, and that's how he'd made his fortune. This is hidden under the tempests, more tempests, the tempests of the novel. "

This was written in 1994, so I am obviously way out of date, but this was a bit of a revelation for my understanding of the novel. All that brooding soul-searching stuff suddenly seems a little bit less like romantic twaddle.