One of the greatest practical difficulties our armies have experienced has been connected with the system of picketing. The South having been greatly impoverished in those portions traversed by the contending armies, and the people entirely destitute of luxuries, there are innumerable applications from residents outside of the pickets for admission within the lines, in order to trade with officers, for the purpose of procuring in return articles from our well-supplied commissariat. Various other necessities of the people appeal for a modified degree of rigor in regard to picket arrangements, so that our armies are never free from the presence of rebel inhabitants, traversing them in all directions. Perfectly familiar with the country, they are able to detect any weakly guarded places, and undoubtedly, in frequent instances, after receiving the kindest treatment, return to their homes conveying such information to guerillas as enables these prowlers to penetrate through by-roads and seize animals and straggling soldiers. As a precaution against such annoyances, a very judicious arrangement was made last winter by the provost marshal general of the Army of the Potomac. He established certain points on the picket line at which traffic might be conducted, and forbade admission to citizens. Some rigorous system like this is very necessary. The social life of camps is, however, the topic of chief interest. The question is often asked, Is the life of a soldier demoralizing? The answer must be, 'Yes,' but not for the reasons generally supposed. The opportunities for vice and dissoluteness are really less than at home. The hundred thousand men in an army use less liquor than the same number of men in a city. In fact, liquor is nearly inaccessible to the soldier when on the march. For other kinds of vice the temptations are few. The demoralization arises from the terrible monotony of a prolonged camp, which produces listlessness, indolence, and a devotion to small amusements; deranges and reverses the whole system of active life, as it is seen at home; renders a man uncouth; disqualifies soldiers for anything else than the trade of war. To the officer in his tent and to the soldier in his log hut, while the cold rains are beating without, and the ground is knee deep with mud, there is a constant temptation to find amusement in cards. Gambling thus becomes a pastime too generally adopted. The books sent to the army are not always of the character best adapted to the circumstances. Moral essays and tracts will not be very eagerly sought for by men whose principal object is to kill time. The reading matter needed is the kind afforded by the periodicals of the day, unobjectionable novels, biographies, works of travel, etc.