I have always assumed that if I am steaming, say carrots, I can get away with using my municipal tap water, with its poisons countered by its chlorine (yuchh) because all that touches the carrrots is the pure steam, and the impurities stay below. As in steam distillation. However, if I'm cooking the carrots IN the water, I will use purified water. But now I read in "The Essence of Cookery" by Rumohr (1822) of the glories of steaming with stock, which suggests a) a kind of cooking I had never known and b) that the impurities and the chlorine are indeed getting to my steamed carrots. May I please have some comment about (a) and (b)? Thanks.