Last week's article included some coin references in Sherlock Holmes stories. The “Red Headed League” mentions Napoleons – gold coins held in the bank that was about to be broken into. I cannot think of any other references to foreign coins.

I have always heard the rhyme about the Bank of England counterstamped eight reales coins, commonly called "dollars" and worth about four shillings, six pence by weight, read more like this:

"The Bank, to make their dollars for five shillings pass,
stamped the head of a fool on the neck of an ass!"

The "Napoleons" referred to are presumably 20 Franc coins of Napoleon III, not Napoleon Bonaparte, though in reality gold reserves could have included any 19th Century 20 Francs struck up to the date of the story.

In the "Red Headed League," there is also a mention of an unspecified Chinese coin hanging from Jabez Wilson's watch chain.

In "The Valley of Fear" there is a brief mention of counterfeit U.S. gold dollars that "never passed the Philadelphia Mint."