David went on to demonstrate some of the applications of photochemistry. He showed the fluorescence induced by electrical current by holding a fluorescent light tube against a plasma ball lamp, causing it to glow only up to where he was holding it. He also talked about his work in medicine, particularly in photodynamic therapy cancer treatment where dye is injected into the body and irradiated, causing it to become toxic and kill cancer cells. A particularly amusing demonstration involved a glass baby filled with the yellow chemical bilirubin that, in excess, is responsible for jaundice. David showed that it is not normally water soluble by filling the baby with water and shaking vigorously, noting that the liquids didn’t mix. However, after irradiating it with blue light, the bilirubin dissolved in the water and was able to be flushed out. This is how jaundice is cured in newborns.