Locke argues that man would use the goods of his labour to barter with others and appropriate different goods. No man was allowed to appropriate more than he could barter or use. Some goods were worth more than others; for example, maybe one year there is a shortage of corn but an abundance of mutton, obviously the corn has more value and the person who grew the corn therefore more wealth. Locke claims that eventually man agreed to allow a certain metal or jewel common to all, that was not perishable, serve as money to appropriate goods. Locke states "and as different degrees of industry were apt to give men possessions in different proportions, so this invention of money gave them the opportunity to continue and enlarge them" (Locke, 29).
Why would notsimply making use of the lands of a country (i.e. for traveling) make you subject to that country's laws because of the implicit benefits you gain (i.e. safe passage, an efficient road, etc.)? I believe that Locke himself addresses this question from this point of view in a later section of the Second Treatise.