The gold exchange standard differs in several respects from the limping standard. It has been the product of definite purpose and plan in the Philippines and in Mexico and to a certain extent in India. While in British India it has been, like the limping standard, a compromise with existing conditions, it has there, as elsewhere, received a definite form and substance which separated it from the limping standard as evolved in France and in other countries which found themselves with a large amount of legal-tender silver on their hands when the metal had fallen below the official parity. There are two other essential differences between the limping standard and the gold exchange standard. One is that the gold exchange standard contemplates a circulation of token coins of silver without any necessary concurrent circulation of gold or paper. The other is that the gold exchange standard contemplates definite and comprehensive measures to maintain the value of token coins at par with gold instead of relying purely upon custom and scarcity to give them value. The essential principle upon which the exchange standard has been established is that the value of money is governed by the law of supply and demand. So long as supply was indefinite and excessive, as under the system of the free coinage of silver, there was no way of preventing safely and effectively the decline in the gold value of the coins to the bullion value of their silver contents. The moment, however, that Government undertook to limit the supply of coins to the demand for them, it took an important step to separate their value from that of their bullion contents and to give them a value based upon the demand for them as money signs required for carrying on exchanges. Strangely enough, while this principle had been in operation for many years in the case of subsidiary coins, its bearing upon the use of silver in countries where the standard had been depreciating was not clearly comprehended until within recent years. Those who understood the principle doubted its sufficiency to give a fixed value to silver coins as the sole medium of exchange, or they distrusted the ability of any government to judge accurately the number of coins required.