Before talking to Patrick (the museum’s Pharmacy Supervisor) a few weeks ago, I hadn’t thought about the fact that the leeches he keeps in Dr. Thrall’s Pharmacy need to be fed. Because we do not actually treat patients with leeches at the museum, every few months we provide the leeches with something non-human to eat. Patrick has found that chicken liver makes a tasty meal for the leeches. I visited the Pharmacy on the day that Patrick fed the leeches; a group of schoolchildren was in the building on a fieldtrip and also had the opportunity to watch. The leeches latched themselves onto the liver and fed for about half an hour. A helpful tip from Patrick: if you are ever trying to remove a leech from yourself or someone else, try sprinkling salt on it or touching it with something hot. Nineteenth-century doctors used leeches to remove poisons and impurities in the blood, which they believed were the cause of a variety of diseases. By 1845, fewer doctors were still using leeches based on new medical information. Leeches aren’t just a medical tool of the past, though; today doctors have renewed their use for leeches to help remove blood from black eyes and other bruises, as well as in microsurgery like reattaching fingers to thin the blood and prevent clots. To see more of the leeches, check out our Facebook photo album, or – even better – stop by and see them for yourself at the pharmacy. You can also learn more about leeches and current medical practices from the company that supplies the pharmacy, Leeches U.S.A.