Differences in the chemical composition of urine caused by changes in diet mean that many medieval recipes for paint etc don’t work right unless you get the urine from someone whose diet resembles a medieval one. (Tested in illuminated manuscript labs, thank you book historians!)
#renfacts Throughout the Middle Ages and Renaissance urine as source of ammonia remained vital to many processes including bleaching, tanning leather, dying, fertilizer, tinting pigment, & making gunpowder mittelzeit.blogspot.com/2014/06/mediev…
