When standard gold bullion is at the lowest price it can be at London, it is worth the mint price, or 3_l._ 17_s._ 10½_d._ _per_ troy ounce, which, expressed in decimals, is 3.8937_l._ sterling. Standard is to fine, as 11 is to 12; consequently, the ounce fine is 4.2476_l._ sterling: and if the Paris ounce of _fine_ bullion be worth, as has been said, 92.5562 livres, the ounce troy, according to the above proportion, will be worth 93.926 livres. Divide then the livres by the sterling money, and the quotient will give you the real par of exchange of the pound sterling, while bullion remains at that value in Paris and in London, viz. 4.2476⁄93.926 = 22.112 livres for the pound, or 32.56_d._ sterling for the French crown of 3 livres. Gold bullion never can rise in the Paris market, at least all the last war it never _did_ rise, above the value of the coin; that is, to 801.6 livres the mark fine, or 100.2 livres _per_ ounce Paris, and 101.7 livres the troy ounce. How high the price of gold bullion may rise at London no man can say; but the highest it rose to, during the last war, was, I believe, 4_l._ 0_s._ 8_d._ _per_ ounce standard, or to 4.3999_l._ sterling _per_ ounce fine. By this divide the value of the ounce troy fine in French livres, the real par at this rate of the metals in both cities will be 4.3999⁄101.7 = 23.11 livres for the pound sterling, or 31.155 pence sterling for the French crown of 3 livres. But suppose two cases which may happen, viz. 1. That gold bullion at Paris should be at the price of coin, while at London it may be at mint price: or, 2. That at Paris it may be at mint price, when at London it is at 4_l._ 0_s._ 8_d._ what will then the real par of exchange be? I answer, that on the first supposition, it will be one pound sterling, equal to 23.939 livres, and the crown of 3 livres equal to 30.076 pence sterling. In the other, equal to 21.34 livres for the pound sterling, and for the crown of 3 livres 33.728. A difference of no less than 8.9 _per cent._ Is it not evident that these variations _must_ occur in the exchange between London and Paris? And is it not also plain, that they proceed from the fluctuation of the price of bullion, not from exchange? We have, I think, demonstrated, in the third book, that a wrong balance upon the French trade raises bullion to the price of coin; and that a right balance brings it down to mint price. The price of coinage is above 8 _per cent._ So that 8 _per cent._ of fluctuation in the price of bullion is easily accounted for in the Paris market, without combining the variations in the English market. In London, where no coinage is paid, were all the coin of full weight, and exportation free, coin and standard bullion would constantly stand at the same price: but when the heavy coin is exported, and the currency becomes light by the old remaining in circulation, the price of bullion rises in proportion.