A famous law-book call’d the Mirrour of Justice, discoursing of the articles (or laws) ordained by our ancient kings, declares the law to be as follows:  It was ordained that no king of this realm should change, impair, or amend the money or make any other money than of gold or silver without the assent of all the counties, that is, as my Lord Coke says, without the assent of Parliament.

This book is very ancient, and of great authority for the time in which it was wrote, and with that character is often quoted by that great lawyer my Lord Coke.  By the laws of England, several metals are divided into lawful or true metal and unlawful or false metal; the former comprehends silver or gold, the latter all baser metals:  that the former is only to pass in payments appears by an Act of Parliament made the twentieth year of Edward the First, called the statute concerning the passing of pence, which I give you here as I got it translated into English; for some of our laws at that time were, as I am told, writ in Latin:  Whoever in buying or selling presumeth to refuse an half-penny or farthing of lawful money, bearing the stamp which it ought to have, let him be seized on as a contemner of the king’s majesty, and cast to prison.

By this statute, no person is to be reckoned a contemner of the king’s majesty, and for that crime to be committed to prison, but he who refuses to accept the king’s coin made of lawful metal, by which, as I observ’d before, silver and gold only are intended.

That this is the true construction of the Act, appears not only from the plain meaning of the words, but from my Lord Coke’s observation upon it.  By this Act (says he) it appears that no subject can be forc’d to take in buying or selling or other payments, any money made but of lawful metal; that is, of silver or gold.

The law of England gives the king all mines of gold and silver, but not the mines of other metals; the reason of which prerogative or power, as it is given by my Lord Coke, is, because money can be made of gold and silver, but not of other metals.

Pursuant to this opinion half-pence and farthings were anciently made of silver, which is more evident from the Act of Parliament of Henry the IVth. chap. 4, by which it is enacted as follows:  Item, for the great scarcity that is at present within the realm of England of half-pence and farthings of silver, it is ordained and established that the third part of all the money of silver plate which shall be brought to the bullion, shall be made in half-pence and farthings.  This shows that by the words half-penny and farthing of lawful money in that statute concerning the passing of pence, is meant a small coin in half-pence and farthings of silver.

This is further manifest from the statute of the ninth year of Edward the IIId. chap. 3, which enacts, That no sterling half-penny or farthing be molten for to make vessel, or any other thing by the goldsmiths, nor others, upon forfeiture of the money so molten (or melted).