The Wealth of Nations by Part 1 Chapter 4 Page 13

and fineness with the English pound sterling. English, French, and Scots pennies, too, contained all of them originally a real pennyweight of silver, the twentieth part of an ounce, and the two-hundred-and-fortieth part of a pound. The shilling too seems originally to have been the denomination of a weight. When wheat is at twelve shillings the quarter, says an ancient statute of Henry III, then wastel bread of a farthing shall weigh eleven shillings and four pence.

The proportion, however, between the shilling and either the penny on the one hand, or the pound on the other, seems not to have been so constant and uniform as that between the penny and the pound. During the first race of the kings of France, the French sou or shilling appears upon different occasions to have contained five, twelve, twenty, and forty