INTERNATIONAL SANITARY CONVENTION. JUNE 21,1926. (6) The sanitary authority mar order deratisation before the discharge of cargo, if it is of opimon, having regard to the nature of the cargo, and the way in which it is loaded, that it is possible to effect a total destructIon of rats without removi~ it. In this ease, the ship cannot be subjected to a new deratisation after dis- charge. In other cases the complete destruction of rats on board must be effected when the holds are empty. In the ca.ses of ships in ballast, this shall be done as soon as possible before taking cargo. Destruction of rats shall be carried out so as to avoid, as far as possible, damage to the ship and cargo (if any). The operation must not la!t longer than twenty-four hours. All charges made in respect to these operations of deratisation as also all contingent indemnity claims,· shall be settled in accordanoe with the principles laid down in Article 18. H a ship is only to disch~e a part of its cargo, and if the port authorities consider that it IS impossible to undertake complete deratisation, the said ship shall be allowed to remain in the port for the time required to discharge that part of its cargo, provided that all precautions, including isolation, are taken to the satisfaction of the sanitary authority to prevent rats from passing from ship to shore, either with unladen goods or otherwise. The discharge of cargo shall be carried out under the supervision of the sanitary authority, who shall take all measures necessQ.1Y to ~revent the men employed on this dut.Y from becoming infected. The men shall be sublected. to observation or to surveillance for a period not exceeding SIX days from the time when they have ceased to work at the unloading of the ship. ARTICLE 26. 2563 Rat destruction. Discharge ot cargo. Plague-suspected ships shall undergo the measures indicated in .J~~Kue luspected Nos. 1,4/5 and 6 of Article 25. S III t In addition] the crew and passengers may be subjected to surveil- andU;Va:se=.o c re w lance which shall not exceed six days, reckoned from the date of the ship's arrival. The crew may be prevented during the same period from going ashore. except on duty made known to the Sanitary Authority. ARTICLE 27. Ships uninfected with :plague shall be ¢ven free pratique imme- Unlntected shipe. diately, with the reservatIOn that the sanItary authority of the port of urival may prescribe the following measures with regard to them: (1) Medical inspection to determine whether the condition of the ship cOITesponds to the definition of a healthy ship; (2) Destruction of rats on board under the conditions specified in 6 of Article 25 in exceptional eases and for well-founded re(l.Sons which will be communicai.ed in writing to the Captain of the ship; Surveillance of crew (3) The crew and passengers may be subjected to surveillance and Jl8SMDI!8lS. during a period which shall not exceed six days reckoned from the date on which the ship left the contaminated :port. The crew may be prevented during t/he same period from gomg ashore except on duty made known to the sanitary authority. ARTICLE 28. All ships, except those employed in national coastwise service, odt~:urer:Us!d perl. must be periodically deratisedl 01' be permanently kept in such a . condition that rat :populatio~ IS . reduced. to the miniJ!lum. In the first ease they receIve Deratisation Certificates, and In the seCond Deratisation Exemption Certificates.