We have been for some days, in much inquietude for the Count de Vergennes.  He is very seriously ill.  Nature seems struggling to decide his disease into a gout.  A swelled foot, at present gives us a hope-of this issue.  His loss would at all times have been great; but it would be immense during the critical poise of European affairs, existing at this moment.  I enclose you a letter from one of the foreign officers, complaining of the non-payment of their interest.  It is only one out of many I have received.  This is accompanied by a second copy of the Moorish declaration sent me by Mr. Barclay.  He went to Alicant to settle with Mr. Lambe; but on his arrival there, found he was gone to Minorca.  A copy of his letter will inform you of this circumstance, and of some others relative to Algiers, with his opinion on them.  Whatever the States may enable Congress to do for obtaining the peace of that country, it is a separate question whether they will redeem our captives, how, and at what price.  If they decide to redeem them, I will beg leave to observe, that it is of great importance that the first redemption be made at as low a price as possible, because it will form the future tariff.  If these pirates find that they can have a very great price for Americans, they will abandon proportionably their pursuits against other nations, to direct them towards ours.  That the choice of Congress may be enlarged, as to the instruments they may use for effecting the redemption, I think it my duty to inform them, that there is here an order of priests called the Mathurins, the object of whose institution is to beg alms for the redemption of captives.  They keep members always in Barbary, searching out the captives of their country, and redeem, I believe, on better terms than any other body, public or private.  It occurred to me, that their agency might be obtained for the redemption of our prisoners at Algiers.  I obtained conferences with the General, and with some members of the order.  The General, with all the benevolence and cordiality possible, undertook to act for us if we should, desire it.  He told me that their last considerable redemption was of about three hundred prisoners, who cost them somewhat upwards of fifteen hundred livres apiece.  But that they should not be able to redeem ours, as cheap as they do their own; and that it must be absolutely unknown that the public concern themselves in the operation, or the price would be greatly enhanced.  The difference of religion was not once mentioned, nor did it appear to me to be thought of.  It was a silent reclamation and acknowledgment of fraternity, between two religions of the same family, which historical events of ancient date had rendered more hostile to one another, than to their common adversaries.  I informed the General, that I should communicate the good dispositions of his order, to those who alone had the authority to decide whatever related to our captives.  Mr. Carmichael informs me, that monies have been advanced for the support of our prisoners at Algiers, which ought to be replaced.  I infer from the context of his letter, that these advances have been made by the court of Madrid.  I submit the information to Congress.