The use of poison, of projectiles or weapons inflicting unnecessary suffering, is prohibited.[342] The Hague Conference also declared against the "use of projectiles, the object of which is the diffusion of asphyxiating or deleterious gases."[343]
Retaliation, devastation, refusal of quarter, and other severe methods once resorted to are now generally forbidden, except as punishment for violation of the laws of war.
[§ 110. Privateers]
A private armed vessel owned and manned by private persons and under a state commission called a "letter of marque,"[344] is a privateer.
This method of carrying on hostilities has gradually met with less and less of favor.[345] From the early days of the fifteenth century neutrals were given commissions. Toward the end of the eighteenth century treaties and domestic laws gradually provided against this practice, though letters of marque were offered to foreigners by Mexico in 1845, and by the Confederate States in 1861-1865. These were not accepted, however, as such action had then come to be regarded as piracy by many states. Privateering of any kind, as Kent said, "under all the restrictions which have been adopted, is very liable to abuse. The object is not fame or chivalric warfare, but plunder and profit. The discipline of the crews is not apt to be of the highest order, and privateers are often guilty of enormous excesses, and become the scourge of neutral commerce.... Under the best regulations, the business tends to blunt the sense of private right, and to nourish a lawless and fierce spirit of rapacity."[346] The granting of letters of marque to private persons of either of the belligerent states was attended with grave evils, and, by the Declaration of Paris, 1856, "Privateering is, and remains, abolished."[347] This declaration was agreed to by the leading states of the world, with the exception of the United States, Spain, Mexico, Venezuela, and China. In the Spanish-American War of 1898 the United States formally announced that it would not resort to privateering.[348] Spain, while maintaining her right to issue letters of marque, declared the intention to organize for the present (May 3, 1898) a service of "auxiliary cruisers of the navy." The importance of the subject of privateering is now largely historical, as it is doubtful whether any civilized state would resort to this method of carrying on maritime war.
[§ 111. Voluntary and Auxiliary Navy]
The relations of private vessels to the state in time of war, which had been settled by the Declaration of Paris in 1856, was again made an issue by the act of Prussia in the Franco-German War. By a decree of July 24, 1870, the owners of vessels were invited to equip them for war and place them under the naval discipline. The officers and crews were to be furnished by the owners of the vessels, to wear naval uniform, to sail under the North-German flag, to take oath to the articles of war, and to receive certain premiums for capture or destruction of the enemy's ships. The French authorities complained to the British that this was privateering in disguise and a violation of the Declaration of Paris. The law officers of the crown declared that there was a "substantial difference" between such a volunteer navy and a system of privateering, and that the action of Prussia was not contrary to the Declaration of Paris. With this position some authorities agree, while others dissent.[349] The weight of the act as a precedent is less on account of the fact that no ships of this navy ever put to sea. Similarly, the plan of Greece for a volunteer navy in 1897 was never put into operation.[350]
Russia, in view of possible hostilities with England in 1877-1878, accepted the offer of certain citizens to incorporate into the navy during the war vessels privately purchased and owned. Such vessels are still numbered in the "volunteer fleet," and though privately owned and managed are, since 1886, under the Admiralty. These vessels may easily be converted into cruisers, and are, so far as possible, favored with government service. There seems to be little question as to the propriety of such a relationship between the state and the vessels which may be used in war.
Still less open to objection is the plan adopted by Great Britain in 1887 and by the United States in 1892, by which these governments, through agreements with certain of their great steamship lines, could hire or purchase at a fixed price specified vessels for use in case of war. The construction of such vessels is subject to government approval, and certain subsidies are granted to these companies. In time of war both officers and men must belong to the public forces. The plans of Russia, Great Britain, and the United States have met with little criticism.[351]