§ If we examine the history of the earlier stages of society, we shall see the constant tendency of its institutions to facilitate the mutual exchange of commodities between its members, and to remove every obstacle impeding their interchange. When the population was thinly scattered over the country, the possessor of a fowl, wanting a pound of butter, was obliged to go some distance to a neighbour either to purchase the butter or to get it in exchange for the fowl. But it would have cost him more time than the worth of the butter if he had visited several neighbours to find out where it was the cheapest. To remedy this inconvenience, market days were established in the villages and towns at more or less frequent intervals. On these occasions each farmer sent one of the family to the periodic market, who sold the produce of the farm and purchased whatever might be required of their neighbours, who were each represented by one of their own family at that common market. Itinerant vendors of various manufactured articles flocked to these markets because they there met their customers with less loss of time and less fatigue. Whilst these hawkers thus gained on the one hand, it must be admitted that they lost on the other those occasionally extravagant profits sometimes levied on the necessities of their isolated customers. But on the whole they derived from their trade a more regular rate of profit, because the competition side by side of rival goods and rival prices, rendered that profit much less fluctuating. Their greatest gain, however, arose from the time saved by all parties, which largely increased the consumption of their respective articles of produce. § When towns became enlarged, the same principle of mutual interest led to the selection of particular streets or quarters of the town by particular trades. In many cities on the continent, the jewellers, as well as some other trades, still occupy entire streets by themselves. The next step seems to have been to hold a general exchange in a fixed spot at certain periodic times. This was necessary for the merchants and larger dealers, and for international exchanges. In great cities this was again subdivided into various branches of business, as—The Corn Exchange—The Coal Exchange, &c. § At these marts a class of men called brokers arose, whose business it was to sell on commission for the producers, and to purchase on commission for the merchants or other middle men. The economy of time produced by this arrangement is very great. Let us suppose an exchange or bazaar attended by a hundred purchasers and a hundred sellers. Each purchaser, in order to become fully acquainted with the state of the market, must ask at least two questions of each seller— 1st. What is the price? 2d. What quantity have you for sale at that price?