At the time when the defendant made his contract with the plaintiffs, the only legal currency of the United States was gold and silver coin. This has not ceased to be the lego, currency of the country at any time since. It is evident from *369these considerations that, if he has retained the amount due him by his contract in the gold coin of the country, he has received no more than he was equitably as well as legally entitled to have. The laws authorizing the issue of United States treasury notes, and making them a legal tender in payment of debts, have not made the gold coins of the denomination of one or more dollars a legal tender for any more than the dollars they represent. Because a treasury note, which bears in popular estimation a less value than a gold coin of the same denomination, will pay a debt, the gold coin will not overpay it.
If one man has received to another’s use a certain sum of money, in the currency recognized by law as the currency of the country, judgment can be rendered against him only for that sum ; and if he has been paid a certain number of dollars in the legal currency of the country, it is only a payment of that number of dollars, although some other kind of currency than that in which he was paid might have been more cheaply obtained. The coined dollar of gold, fixed by law as of the value of a dollar, cannot be treated by any judicial tribunal, in any eomputatation or judgment, as having another or different value. Wood v. Bullens, 6 Allen, 516.
The defendant’s credits were therefore clearly right, so far as he retained the sums due to him in the coined money of the United States.
The payments retained in English sovereigns, or gold coins reckoned in pounds sterling, are not governed by a rule so simple in its application. But in respect to them the rule is clearly settled. When a debt is due or a payment made in the currency of a foreign country, its amount is to be computed in the -urrency of the United States according to the real par of exchange; that is, by ascertaining what sum the standard coin of one will produce of equal weight and fineness in the currency of the other. Commonwealth v. Haupt, 10 Allen, 38. Hussey v. Farlow, 9 Allen, 263. This is an absolute standard, not liable to vary with the causes which produce fluctuations of exchange ; and, in the absence of any special contract, appears to be the most practical and just. In Hussey v. Farlow, the rule *370was applied to payments made under a charter party in pounds sterling; and we think there is nothing in principle to distinguish that case from the case at bar.
The defendant will have judgment for the amount found due upon his set-off according to the auditor’s report.