Letter from the Secretary of the Treasury, transmitting the result of assays made at the Mint of the United States, of the several species of foreign coins, current, by law...
U.S. Mint Reports (1822)
A report from the Director of the Mint (Robert Patterson) on the assay of foreign coins. The same text is in the American State Papers, finance (class 3), volume 4, report no. 655.
Paul Hybert summary: "An assay of foreign silver coins, from mint director Robert Patterson to Treasury Secretary Crawford, who relayed it to Congress. The recent assay results for the three types of foreign silver coins still current are stated — they are consistent with prior results."
A transcription is at: http://www.chicagocoinclub.org/lib/us/asp/cl03.finance/v4/n655.html.