§ 56. If a citizen of the United States obtains information in a legitimate manner, and betrays it to the enemy, be he a military or civil officer, or a private citizen, he is a traitor, and is condemned to death. § 57. All unauthorized and secret communication with the enemy, is considered treasonable by the Law of War. § 58. A messenger carrying despatches, in whatever form, from one portion of the army, or from a besieged place, to another portion of the same army, or its government—if captured while doing so, in the enemy’s territory, or in the territory occupied by the enemy, is treated by the capturing enemy as a spy. The same fate awaits such messenger, although he may not have any written despatch about him, when it can be proved that he is the carrier of verbal messages. This does not apply to armed troops, ready to fight their way through, although they may carry messages. § 59. If it be discovered, and fairly proved, that a flag of truce has been abused for the surreptitious obtaining of military knowledge, the bearer of the flag thus abusing his sacred character, is deemed a spy. So sacred is the character of a flag of truce, and so necessary is its sacredness, that while its abuse is an especially heinous offence, great caution is requisite, on the other hand, in convicting the bearer of a flag of truce of this crime, and in punishing him accordingly. § 60. The Law of War, like the Criminal Law regarding other offences, makes no difference on account of the difference of sexes, concerning the spy, the traitor, or the war-rebel. § 61. Spies, traitors, and war-rebels are not exchanged according to the common law of war. The exchange of such persons would require a special cartel, authorized by the President of the United States, or, at a great distance from the United States, by the chief commander of the army in the field. EXCHANGE OF PRISONERS. FLAGS OF TRUCE. FLAGS OF PROTECTION. § 62. Exchanges of prisoners take place with prisoners of war only—number for number—rank for rank—wounded for wounded—with added condition for added condition—such, for instance, as not to serve for a certain period. § 63. In exchanging prisoners of war, such numbers of persons of inferior rank may be substituted as an equivalent for one of superior rank, as may be agreed upon by cartel, which requires the sanction of the President of the United States, or of the commander of the army in the field. § 64. A prisoner of war is in honor bound truly to state to the captor his rank, and not to assume a lower rank than belongs to him, in order to cause a more advantageous exchange; nor a higher rank, for the purpose of obtaining better treatment. Offences to the contrary have been justly punished by the commanders of released prisoners.