E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
March Dust.
A bushel of March dust is worth a king’s ransom. According to the Anglo-Saxon laws, the fine of murder was a sliding scale proportioned to the rank of the person killed. The lowest was £10, and the highest £60; the former was the ransom of a churl, and the latter of a king.
