Gresham's law
One of the concerns of the Irish discussed in the first letter was over what is now known as Gresham's law: debased coins would cause silver and gold coinage to be hoarded or removed from the country, which would further debase the currency. Tenant farmers would no longer be able to pay their landlords, and, after the tenants were removed, there would be fewer crops grown in Ireland; the increase of poverty and the decrease of food supply would completely ruin Ireland's economy.