Christian's now rigid countenance relaxed into the radiant smile which betokened his highest mood of faith. The movement, whether of body or spirit, summoned his pain; but its very first touch released him. He left the greatest of this world's potentates treasuring up the forgiveness of a feeble child, and wondering, as at a new thought, that one who had power over millions of lives should have no more interest than others with the supreme Lord of Life. _Summary of Principles illustrated in this Volume._ Nations exchange commodities, as individuals do, for mutual accommodation; each imparting of its superfluity to obtain that in which it is deficient. The imparting is therefore only a means of obtaining. Exportation is the means of obtaining importation,--the end for which the traffic is instituted. The importation of money into a country where money is deficient is desirable on the same principle which renders desirable the supply of any deficient commodity. The importation of money into a country where money is not deficient is no more desirable than it is to create an excess of any other commodity. That money is the commodity most generally bought and sold is no reason for its being a more desirable article of importation than commodities which are as much wanted in the country which imports it. That money is the commodity most generally bought and sold is a reason for its being the commodity fixed upon for measuring the relative amounts of other articles of national interchange. Money bearing different denominations in the different trading countries, a computation of the relative values of these denominations was made in the infancy of commerce, and the result expressed in terms which are retained through all changes in the value of these denominations. The term by which in each country the original equal proportion was expressed is adopted as the fixed point of measurement called the par of exchange; and any variation in the relative amount of the total money debts of trading nations is called a variation from par. This variation is of two kinds, nominal and real. The nominal variation from par is caused by an alteration in the value of the currency of any country, which, of course, destroys the relative proportion of its denominations to the denominations of the currency of other countries. But it does not affect the amount of commodities exchanged. The real variation from par takes place when any two countries import respectively more money and less of other commodities, or less money and more of other commodities. This kind of variation is sure to correct itself, since the country which receives the larger proportion of money will return it for other commodities when it becomes a superfluity; and the country which receives the smaller proportion of money will gladly import more as it becomes deficient. The real variation from par can never therefore exceed a certain limit.