26. Used fungus and human waste to start fires
In the boy and girl scouts, they are taught multiple ways to start a fire. One of them is the useful invention of a Firestarter, one scrape of the stone and voila, fire! In the 10th century, however, there wasn’t the modern convenience such as a Firestarter or even a flashlight. Instead, Vikings used a fungus called touchwood, a plate-shaped mushroom that grows along tree bark, and boiled it for several days in urine.
That’s right — using a combination of tree fungus and human waste, the Norse would take the urine-boiled fungus and pound it until its texture resembled felt. The sodium nitrate in the urine would allow the material to smolder so Vikings could take the fire with them anywhere (porta-potty has a whole new meaning).