... some people say that charcoal should be added, and others deny it; some recommend a dash of yellow sand because it is supposed to contain iron, while others warn you against it for the very fact that it does contain iron. Others again, recommend clean river sand, others peat alone, and still others sawdust. In short, the preparation of the soil for seeds is a great mystery and a magic ritual.
To it should be added marble dust (but where to get it?), three-year-old cow dung (here it is not clear whether it should be the dung of a three-year-old cow or a three year old heap), a handful from a fresh molehill, clay pounded to dust from old pigskin boots, sand from the Elbe (but not from the Vltabva), three year old hotbed soil, and perhaps besides the humus from the golden fern and a handful from the grave of a hanged virgin.
Karel Capek 1936, as it appears in Peter Loewer's delightful book, SEEDS.
All that should be well mixed (gardening books do not say whether at the new moon, or full, or on midsummer night); and when you put this mysterious soil into flower pots (soaked in water, which for three years have been standing in the sun, and on whose bottoms you put pieces of boiled crockery, and a piece of charcoal, against the use of which other authorities, of course, express their opinions) - when you have done all that, and so obeyed hundreds of prescriptions, principally contradicting each other, you may begin the real business of sowing seeds.