Emily and I are developing our interest in all things germ related having finished our lovely First Light film - The Germinator. Just as well that there's a good exhibition about Dirt at the Wellcome Trust. It features this brilliant image from 1828, dedicated to the London Water Companies, when the Thames was particularly monster soupy. One of the highlights was finding three animations commissioned and owned by the Deutsches Hygiene Museum in Dresden in the 1960's. I've found one on here. You must wash your apple before you eat it, like Snow White, and another one here.
Anthropologist Mary Douglas is quoted in the exhibition: "Dirt is just matter out of place", which reminds me, I have to move some of my matter into a different place.