Let us next examine the proportion between the value of the metals, both in the coin and at the mint.
For this purpose we must compare the mint prices in one equation, and the value of the gold and silver coin in another.
At the mint, a marc of fine silver is paid 51.162 livres, and a marc of fine gold 740.409 livres; consequently 51.162 : 740.409 :: 1 : 14.47.
A marc of fine silver, in the coin, is worth 55.38 livres; a marc of fine gold, in the coin, is worth 801.68 livres. We may therefore state thus, 55.38 : 801.68[801.68] :: 1 : 14.47.
The proportion is as 1 to 14.47.
The proportion, therefore, both at the mint and in the coin is the same; and is nearly as the French writers state it, to wit, as 1 is to 149⁄19, but more exactly as 1 to 14.47, which is very nearly as 1 to 14.5.
Gold contained in a louis d’or, and silver in a crown of 6 livres.
From these computations we find the exact quantity of fine gold in a louis d’or, and of fine silver in a great crown, or piece of 6 livres.
In the louis d’or there are 137.94 grains fine, and 153.1 standard gold.