—— . The departure of Captain Back for the humane purpose of en devouring to trace the fate of Captain Ross and his adventurous companions in the polar regions, will take place in the course of the ensuing week. Captain Back will be accompanied by Mr. King, a surgeon, but who does not belong either to the army or the Royal Navy, and some other individuals, two of whom were with Captain Back in his last journey to that inhospitable part of the globe. They proceed in the first instance to Liverpool, and there embark on board the Hibernia, one of the packet-ships between that port and New York, from which through Canada to Cumberland-house, one of the posts belonging to the Hudson's Bay Company, thence to Slave Lake, and at the proper season to Point Lurn again, where the discoveries in the Hyperborean seas under Captain Franklin terminated. Not long since Cap tain Back was sent for to Brighton, and there had a long audi ence with his Majesty, and explained the whole of the measures to be pursued in the undertaking,which met with the King’s full approbation, and who was graciously pleased to express his ar dent wishes for the success of the expedition. Captain Buck has also had a long audience with his Royal Highness the Duke of Sussex, who, as usual, takes a lively interest in everything relating to the furtherance of science and humanity.