The Act of Union of 1800 had ensured the economic unity of the British Isles. The union of England and Scotland was already a century old, and Smith regarded it as “one of the chief causes of the prosperity of Great Britain.”[568] France had accomplished the same end by the suppression of domestic tariffs in 1791. But Germany even in 1815 was still a congeries of provinces, varying in importance and separated from one another by tariff walls. List, in the petition which he addressed in 1819 to the Federal Assembly in the name of the General Federation of German Trade and Commerce, could reckon no less than thirty-eight kinds of tariffs within the German Confederacy, without mentioning other barriers to commerce. In Prussia alone there were no fewer than sixty-seven different tariffs.[569] “In short,” says List in another petition, “while other nations cultivate the sciences and the arts whereby commerce and industry are extended, German merchants and manufacturers must devote a great part of their time to the study of domestic tariffs and taxes.”[570] These inconveniences were still further aggravated by the complete absence of import duties. The German states were closed to one another, but, owing to the absence of effective central control, were open to other nations—a peculiarly galling situation on the morrow of the Continental Blockade. The peace treaty was scarcely signed when England—so long cut off from her markets and forced to over-stock her warehouses with her manufactured goods—began to flood the Continent with her products. Driven from France by the protective tariff established by the Restoration Government, these goods, offered at ridiculously low prices, found a ready market in Germany. The German merchants and manufacturers became thoroughly alarmed, and there arose a general demand for economic unity and a uniform tariff. Public opinion urged a reform which appeared to be the first step in the movement towards national unity. In 1818 Prussia secured her own commercial unity by abolishing all internal taxation, retaining only those duties which were levied at the frontier. Her new tariff of 10 per cent. on manufactured goods, with free entrance for raw material, was not regarded as prohibitive, and was actually approved of by Huskisson as a model which the British Parliament might well imitate. But this reform, confined as it was to Prussia alone, did nothing to improve the lot of the German merchants elsewhere, for the Prussian tariff applied just as much to them as to foreigners.