§ 114. The First Hague Peace Conference adopted likewise a Declaration, signed on July 29, 1899, prohibiting _for a term of five years_ the launching of projectiles or explosives from balloons or other kinds of aerial vessels. The Second Peace Conference, on October 18, 1907, renewed this Declaration _up to the close of the Third Peace Conference_, but out of twenty-seven States which signed the Declaration only seven--namely, Great Britain, the United States of America, China, Holland, Bolivia, Salvador, Haiti (Nicaragua acceded later)--ratified it, and Germany, France, Italy, Japan, Russia--not to mention smaller Powers--did not even sign it. There is, therefore, no doubt that the Third Peace Conference will not renew the Declaration. Although it is very much to be regretted, the fact must be taken into consideration that in future violence directed from air-vessels will play a great part in war. For this reason, the question as to the conditions under which such violence is admissible, is of importance,[240] but it is as yet impossible to give a satisfactory answer. The Institute of International Law, at its meeting at Madrid in 1911, adopted the principle[241] that _aerial warfare must not comprise greater danger to the person and the property of the peaceful population than land or sea warfare_. However this may be, there can be no doubt that the general principles laid down in the Declaration of St. Petersburg of 1868, in the two Declarations, adopted by the First Peace Conference, concerning expanding bullets and projectiles diffusing asphyxiating or deleterious gases, in the Hague rules concerning land warfare, and the like, must find application as regards violence directed from air vessels. [Footnote 240: See, besides the literature quoted above, vol. I. p. 237, note 1, Mérignhac, pp. 198-209; Bonfils, Nos. 1440'4-1440'21; Despagnet, No. 721 _bis_; Meyer, _Die Luftschiffahrt in kriegsrechtlicher Beleuchtung_ (1909); Philet, _La guerre aérienne_ (1910); Nys, Fauchille, and Bar in _Annuaire_, XIX. (1902), pp. 58-114, XXIV. (1911), pp. 23-126; Fauchille in _R.G._ VIII. (1901), pp. 414-485.] [Footnote 241: See _Annuaire_, XXIV. (1911), p. 346.] [Sidenote: Violence against non-combatant Members of Armed Forces.]