§ 209_b_. Convention X. comes into force sixty days after ratification or accession on the part of each Power concerned (article 26). It replaces the Convention of 1899 for the adaptation to naval warfare of the principles of the Geneva Convention, but this latter Convention remains in force between such of its contracting parties as do not become parties to Convention X. (article 25). Such non-signatory Powers of Convention X. as are parties to the Geneva Convention of 1906 are free to accede at any time, and a Power desiring to accede must notify its intention in writing to the Dutch Government which must communicate the accession to all the contracting Powers (article 24). Each of the contracting Powers is at any time at liberty to denounce Convention X. by a written notification to the Dutch Government which must immediately communicate the notification to all the other contracting Powers; the denunciation, however, does not take effect until one year after the notification has reached the Dutch Government, and a denunciation only affects the Power making the notification (article 27). A register kept by the Dutch Minister of Foreign Affairs must record the dates of the deposit of ratifications, as well as the dates of accessions or of denunciations; each contracting Power is entitled to have access to this register and to be supplied with duly certified extracts from it (article 28). VI ESPIONAGE, TREASON, RUSES See, besides the literature quoted above at the commencement of §§ 159 and 163, Pradier-Fodéré, VIII. No. 3157, and Bentwich in _The Journal of the Society of Comparative Legislation_, New Series, X. (1909), pp. 243-249. [Sidenote: Espionage and Treason.] § 210. Espionage[419] and treason do not play as large a part in sea warfare as in land warfare;[420] still they may be made use of by belligerents. But it must be specially observed that, since the Hague Regulations deal only with land warfare, the legal necessity of trying a spy by court-martial according to article 30 of these Regulations does not exist for sea warfare, although such trial by court-martial is advisable. [Footnote 419: As regards the case of the _Haimun_, see below, § 356.] [Footnote 420: See above, §§ 159-162.] [Sidenote: Ruses.]