From what has been said, it will be seen that the wealth of a country may be increased in two ways: it may be increased by employing a greater portion of revenue in the maintenance of productive labour, which will not only add to the quantity, but to the value of the mass of commodities; or it may be increased, without employing any additional quantity of labour, by making the same quantity more productive, which will add to the abundance, but not to the value of commodities.