An Act to empower His Majesty to cause certain contervailing Duties, granted by an Act of the Thirty-seventh Year of the Reign of His present Majesty, intituled, An Act for carrying into Execution the Treaty of Amity, Commerce, and Navigation, concluded between His Majesty and the United States of America, to cease, or be suspended until the Twenty-fifth Day of March One thousand eight hundred and three, under certain Circumstances.