A matter which grew out of privateering gave Franklin much trouble. The American captains, who were cruising on the European side of the Atlantic prior to the treaty of alliance with France, had no place in which to deposit their prisoners. They could not often send them to the States, neither of course could they accumulate them on board their ships, nor yet store them, so to speak, in France and Spain; for undeveloped as were the rules of neutrality they at least forbade the use of neutral prisons for the keeping of English prisoners of war in time of peace. Meanwhile the colonial captives, in confinement just across the Channel, in the prisons at Plymouth and Portsmouth, were subjected to very harsh treatment; and others were even being sent to the fort of Senegal on the coast of Africa, and to the East Indies, whence they could not hope ever to regain their homes. Franklin immediately resolved, if possible, to utilize these assets in the shape of English sailors in the usual course of exchange. A letter was accordingly addressed by him to Lord Stormont, asking whether it would be worth while to approach the British court with an offer to exchange one hundred English prisoners in the hands of the captain of the Reprisal for a like number of American sailors from the English prisons. The note was a simple interrogatory in proper form of civility. No answer was received. After a while a second letter was prepared, less formal, more forcible in statement and argument, and in the appeal to good sense and decent good feeling. This elicited from his lordship a brief response: "The king's ambassador receives no applications from rebels, unless they come to implore his majesty's mercy." The commissioners indignantly rejoined: "In answer to a letter which concerns some of the most material interests of humanity, and of the two nations, Great Britain and the United States of America, now at war, we received the inclosed indecent paper, as coming from your lordship, which we return for your lordship's more mature consideration." The technical position of the English in this business was that the captured Americans were not prisoners of war, but traitors. Their practical position was that captains of American privateers, not finding it a physical possibility to keep their prisoners, would erelong be obliged to let them go without exchange. This anticipation turned out to be correct, and so far justified their refusal; for soon some five hundred English sailors got their freedom as a necessity, without any compensatory freeing of Americans. Each of them gave a solemn promise in writing to obtain the release of an American prisoner in return; but he had as much authority to hand over the Tower of London, and the British government was not so romantically chivalrous as to recognize pledges entered into by foremast hands.