=30. Political conditions affecting commerce; the modern system of government.=—The reader who studies the history of commerce in the medieval period faces a system of government entirely different from that of modern times, which he must understand before he can appreciate the peculiar conditions of commerce then. We can illustrate the modern method of government by taking a country, say France, for an example. We wish to understand the relations of the capital, Paris, to other parts of the country, say the district around Bordeaux, in the southwest corner. An observer of this country will find that Paris and Bordeaux are united by different means of communication and transportation, telegraphs and posts, railroads, highways and canals, which are constantly employed in the service of government. On the path from the province to the capital go the reports of the officials who are in charge of the government of Bordeaux; and, if they fail in their duties, petitions and complaints from private citizens, asking relief, will take the same path. By this path, also, the taxes collected at Bordeaux will stream to the treasury at Paris, to be employed in maintaining the government. Part of these taxes will be expended at Paris, to support the officials who live in the capital, the central army, etc. Part, however, must be used to fulfil the local needs of Bordeaux; and on the road from the capital to the province we shall find money and wares, going as salaries to officials, appropriations for public works and the like. On this road, furthermore, we shall find a stream of messages, sent by the central government to its local subordinates, directing them in their work; these messages will answer the reports of officials and the petitions and complaints of subjects. =31. Impossibility of applying modern methods of government in the period after the fall of Rome.=—The system of government, thus roughly outlined, was the system used in the period when Rome was still strong. But when the power of Rome declined it became constantly more difficult to maintain a system of the kind; every obstacle to the free passage of men and wares weakened the hold of the government on its provinces. The roads grew worse, and while they were still passable the danger of traversing them increased, so that the expense of maintaining this government became prohibitive. The reports from officials and the petitions from subjects were delayed or lost; only a small part of the local taxes reached the treasury at the center. The central government, on its side, found that it had no longer the means to pay the bills for salaries and public works in the provinces, and found that its commands were not received there, or were not obeyed, because the government could no longer send officials and troops to force obedience.