If the claim made by Mr. Clay was just when the population of States bordering on the shores of the Lakes was only 3,400,000, it now derives greater force and equity from the increased population, wealth, production, and tonnage of the States on the Canadian frontier.  Since Mr. Clay advanced his argument in behalf of our right the principle for which he contended has been frequently, and by various nations, recognized by law or by treaty, and has been extended to several other great rivers.  By the treaty concluded at Mayence in 1831 the Rhine was declared free from the point where it is first navigable into the sea.  By the convention between Spain and Portugal concluded in 1835 the navigation of the Douro throughout its whole extent was made free for the subjects of both Crowns.  In 1853 the Argentine Confederation by treaty threw open the free navigation of the Parana and the Uruguay to the merchant vessels of all nations.  In 1856 the Crimean War was closed by a treaty which provided for the free navigation of the Danube.  In 1858 Bolivia by treaty declared that it regarded the rivers Amazon and La Plata, in accordance with fixed principles of national law, as highways or channels opened by nature for the commerce of all nations.  In 1859 the Paraguay was made free by treaty, and in December, 1866, the Emperor of Brazil by imperial decree declared the Amazon to be open to the frontier of Brazil to the merchant ships of all nations.  The greatest living British authority on this subject, while asserting the abstract right of the British claim, says:  It seems difficult to deny that Great Britain may ground her refusal upon strict law, but it is equally difficult to deny, first, that in so doing she exercises harshly an extreme and hard law; secondly, that her conduct with respect to the navigation of the St. Lawrence is in glaring and discreditable inconsistency with her conduct with respect to the navigation of the Mississippi.  On the ground that she possessed a small domain in which the Mississippi took its rise, she insisted on the right to navigate the entire volume of its waters.  On the ground that she possesses both banks of the St. Lawrence, where it disembogues itself into the sea, she denies to the United States the right of navigation, though about one-half of the waters of Lakes Ontario.  Erie, Huron, and Superior, and the whole of Lake Michigan, through which the river flows, are the property of the United States.  The whole nation is interested in securing cheap transportation from the agricultural States of the West to the Atlantic Seaboard.  To the citizens of those States it secures a greater return for their labor; to the inhabitants of the seaboard it affords cheaper food; to the nation, an increase in the annual surplus of wealth.  It is hoped that the Government of Great Britain will see the justice of abandoning the narrow and inconsistent claim to which her Canadian Provinces have urged her adherence.