§ 199. Since enemy vessels are liable to capture, the question must be taken into consideration whether the fact that an enemy vessel has been sold during the war to a subject of a neutral or to a subject of the belligerent State whose forces seized her, has the effect of excluding her appropriation. It is obvious that, if the question is answered in the affirmative, the owners of enemy vessels can evade the danger of having their property captured by selling their vessels. The question of transfer of enemy vessels must, therefore, be regarded as forming part of the larger questions of enemy character and has consequently been treated in detail above, § 91. [Sidenote: Goods sold by and to Enemy Subjects during War.] § 200. If a captured enemy vessel carries goods consigned by enemy subjects to subjects of neutral States, or to subjects of the belligerent whose forces captured the vessel, they may not be appropriated, provided the consignee can prove that he is the owner. As regards such goods found on captured enemy merchantmen as are consigned to enemy subjects but have been sold _in transitu_ to subjects of neutral States, no unanimous practice of the different States is in existence. The subject of goods sold _in transitu_ must--in the same way as the question of transfer of enemy vessels--be considered as forming part of the larger question of enemy character. It has, for this reason, been treated above, § 92. IV VIOLENCE AGAINST ENEMY PERSONS See the literature quoted above at the commencement of § 107. See also Bonfils, Nos. 1273-1273'3. [Sidenote: Violence against Combatants.] § 201. As regards killing and wounding combatants in sea warfare and the means used for the purpose, customary rules of International Law are in existence according to which only those combatants may be killed or wounded who are able and willing to fight or who resist capture. Men disabled by sickness or wounds, or such men as lay down arms and surrender or do not resist capture, must be given quarter, except in a case of imperative necessity or of reprisals. Poison, and such arms, projectiles, and materials as cause unnecessary injury, are prohibited, as is also killing and wounding in a treacherous way.[402] The Declaration of St. Petersburg[403] and the Hague Declaration prohibiting the use of expanding (Dum-Dum)[404] bullets, apply to sea warfare as well as to land warfare, as also do the Hague Declarations concerning projectiles and explosives launched from balloons, and projectiles diffusing asphyxiating or deleterious gases.[405] [Footnote 402: See the corresponding rules for warfare on land, which are discussed above in §§ 108-110. See also U.S. Naval War Code, article 3.] [Footnote 403: See above,§ 111.] [Footnote 404: See above, § 112.] [Footnote 405: See above, §§ 113 and 114.]