A licence cannot be _ante dated_, and if granted subsequent to capture it is no protection against condemnation. It is in its very nature prospective, pointing to something which has not yet been done, and cannot be done at all without such permission. Where the act has already been done, and requires to be upheld, it must be by an express confirmation of the act itself, as by an indemnity granted to the party; but a licence necessarily looks to that which remains to be done, and can extend its influence only to future operations.[127] Note.--It has been before pointed out, that the Queen has, by her prerogative, the power of granting licences. But the Navigation Laws could not, of course, be dispensed with by the royal prerogative. Various acts, therefore, were passed to alter or qualify them, according to the new condition of things which was produced in time of war. These acts expired with the several wars that suggested them; but the almost total repeal of the celebrated Navigation Laws will render the re-enactment of similar war measures almost unnecessary. SECTION IV. _Ransom, Recaptures, and Salvage_. [Sidenote: Ransom.] Sometimes circumstances will not permit property captured at sea to be sent into port; and the captor, in such cases, may either destroy it, or permit the original owner to redeem it. It was formerly the general custom to redeem property from the hands of the enemy by Ransom, and the contract is undoubtedly valid, when municipal regulations do not intervene. It is now but little known in the commercial law of England, for several statutes in the reign of George the Third absolutely prohibited British subjects the privilege of ransom of property captured at sea, unless in a case of extreme necessity--to be judged of by the Court of Admiralty.[128] These contracts are generally drawn up at sea, and by virtue of them, the captain of the captor engages for the release and safe conduct of the taken ship, in consideration of a sum of money, which the master of the captured vessel, on behalf of himself and the owners of his ship and cargo, engages to pay, and for the payment of which he delivers a hostage as security. The contract is drawn up in two parts, of which the captor has one, which is called the ransom bill; the master of the captured vessel has the other, which operates as his safe conduct. By the French law this safe conduct only protects the vessel to its own port, or its port of destination, if nearer that. In other countries the pass allows the ship to continue its voyage; but operates only to protect the vessel in the course prescribed, and within the time limited by the contract. It protects only against capture, unless by agreement it provides also against _total loss_ by perils of the seas.