Its true. J. Marion Sims (who the graphic erroneously calls Marion J. Sims) is well known and he is not the only 'slaveholder scientist' to use his human property as experimental fodder and its easy to imagine how the lack of consent made enslaved people a particularly juicy target for medical scientists. Similarly, graverobbing at the Richmond African Burial Ground and NYC African Burial Ground was instrumental to providing experimental cadavers for medical students. Though I study slavery, this is not really a topic I regularly have worked with, but it is definitely something I've encountered in the literature