It was this experience in France, and the allied group of countries, which led to the formation of the Latin Union in 1865. In mere point of date, that union had been preceded by the Vienna Conference and Convention by a matter of eight years. And as far as the regulations of this latter relating to gold coinage are concerned, there is evidence that the bimetallic action of France had driven Germany to her union of 1857, as a mere matter of self-defence, just as it later drove the Latin states to their union of 1865. In both cases the underlying motive was a wish to protect that part of their currency system which was threatened by bimetallic law. The premium on gold, on its minting, i.e. the profit to be made on minting it at 15-1/2 in France, while its market value was considerably less in Germany and elsewhere, drew the gold to France. It is a mistake to think that France attracted gold simply from California and Australia. She attracted it by the action of bimetallic law from her neighbour Germany, and replaced it by 5-franc silver mintings. The circulation of French 5-franc pieces was so extensive in South Germany, in the period preceding the Vienna Convention, that the cash reserve of the Frankfort bank was at one moment composed almost entirely of them. The manner in which the Vienna Convention met the difficulty has the appearance of plausibility, though it proved in the end ineffectual. It determined not to establish a fixed ratio but to follow the market price of gold, apparently in the hope of attracting a natural or market supply. "For the purpose of further facilitating mutual transactions, and for the promotion of trade with neighbouring countries, the contracting powers may coin convention trade coins in gold, under the names _crown_, and _half-crown_. "1. The crown = 1/50 of a pound of fine silver. "2. The half-crown = 1/100. "The contracting powers may not coin any other gold piece, except Austria, which retains the right of coining _ducats_ of the present value, to the end of 1865. "The silver value of the convention gold coins in ordinary intercourse is entirely fixed by the relation of the supply to the demand. They must not, therefore, be considered as a medium of payment of the same nature as the legal silver currency of the country, and no one is legally bound to receive them as such. [Sidenote: THE VIENNA CONVENTION, 1857]