Ch. 1. The importance of external trade -- ch. 2. The alphabet of free exchange -- ch. 3. Exchange between "non-competing groups" -- ch. 4. Nations as trading groups -- ch. 5. Non-protective import duties -- ch. 6. The incidence of protective and preferential duties -- ch. 7. How the balance of imports and exports is achieved -- ch. 8. What a nation buys and what it pays with -- ch. 9. Can protective countires "suck" a free-trade country? -- ch. 10. The mystery of "dumping" -- ch. 11. Protection as a remedy for unemployment -- ch. 12. Protection and socialism.