Two ways may be said to be open by which this quantity can be regulated. One way is to close the Mint and to leave it to the discretion of the Government to manipulate the currency to suit the needs. The other is to keep the Mint open and to leave it to the self-interest of individuals to determine the amount of currency they require. In the absence of unfailing tests to guide the exercise of discretion necessary in the case of closed Mints, the principle of open Mints has been agreed upon as the superior of the two plans. When every individual can obtain coin for bullion and convert coin into bullion, as would be the case under open Mints, the quantity is automatically regulated. If the increasing demands of commerce require a large amount of circulating medium, it is for the interest of the community to divert a larger quantity of its capital for this purpose; if, on the contrary, the state of trade is such as to require less, a portion of the coin is withdrawn, and applied as any other commodity for purposes other than those of currency. Because the Act of 1870 expressly recognized the principle of open Mint, it is not to be supposed that the Mints were closed before that date. As a matter of fact they were open to the free coinage of both gold and silver, although the latter alone was legal tender. But, strange as it may seem, none of the earlier Acts contained a word as to the obligation of the Mint Master to coin all the metal presented to him—a condition which is of the essence of the open mint system. The provisions of the Act on this point are unmistakable. It required:— ⁹⁸ This machinery is provided in England by what is known as the “Trial of the Pyx.” For a history of this institution and the way it functions, cf. H. of C. Return 203 of 1866. During the time of the East India Company the maintenance of the standard purity of the Indian coins always formed a most anxious concern of the Court of Directors. The coins of Indian mintage were regularly required to be sent over to England, where they were tested at a special Trial of the Pyx and the verdict reported back for the future guidance of the Mint Masters in India. Cf. H. of C. Return 14 of 1849. Since the winding-up of the Company there is no machinery to bring the Mint Masters to book. “Section 19. Subject to the Mint-rules for the time being in force, the Mint Master shall receive all gold and silver bullion and coin brought to the Mint: “Provided that such bullion and coin be fit for coinage; “Provided also that the quantity so brought at one time by one person is not less, in case of gold, than fifty tolas, and, in the case of silver, than one thousand tolas.