Discretion, to some extent, in prescribing the value of the coins minted, is beyond doubt vested in congress, but the plain intent of the constitution is that congress, in determining that matter, shall be governed chiefly by the weight and intrinsic value of the coins, as it is clear that if the stamped value of the same should much exceed the real value of gold and silver not coined, the minted coins would immediately cease to be either current coins or a standard of value as contemplated by the constitution. Commercial transactions imperiously require a standard of value, and the commercial world, at a very early period in civilization, adopted gold and silver as the true standard for that purpose, and the standard originally adopted has ever since continued to be so regarded by universal consent to the present time. Paper emissions have, at one time or another, been authorized and employed as currency by most commercial nations, and by no government, past or present, more extensively than by the United States, and yet it is safe to affirm that all experience in its use as a circulating medium has demonstrated the proposition that it cannot by any legislation, however stringent, be made a standard of value or the just equivalent of gold and silver. Attempts of the kind have always failed, and no body of men, whether in public or private stations, ever had more instructive teachings of the truth of that remark than the patriotic men who framed the federal constitution, as they had seen the power to emit bills of credit freely exercised during the war of the Revolution, not only by the confederation, but also by the states, and knew from bitter experience its calamitous effects and the utter worthlessness of such a circulating medium as a standard of value. Such men so instructed could not have done otherwise than they did do, which was to provide an irrepealable standard of value, to be coined from gold and silver, leaving as little upon the subject to the discretion of congress as was consistent with a wise forecast and an invincible determination that the essential principles of the constitution should be perpetual as the means to secure the blessings of liberty to themselves and their posterity. Associated as the grant to coin money and regulate the value thereof is with the grant to fix the standard of weights and measures, the conclusion, when that fact is properly weighed in connection with the words of the grant, is irresistible that the purpose of the framers of the constitution was to provide a permanent standard of value which should, at all times and under all circumstances, consist of coin, fabricated and stamped, from gold and silver, by authority of law, and that they intended at the same time to withhold from congress, as well as from the States, the power to substitute any other money as a standard of value in matters of finance, business, trade, or commerce.