Resigning his appointment with the legation, Kane established himself as a physician at Whampoa, on the Canton River, where illness shortly broke up his professional practice. Fortunately for his future fame he was unsuccessful in his application to the Spanish Government for permission to practise medicine at Manilla, and Kane returned to the United States by the way of Singapore, India, Egypt, and Europe, his journey marked by adventure and danger. In these, as in all other sea voyages, he suffered excessively from sea-sickness, which required all of his indomitable will to endure with equanimity. In 1846 he was commissioned assistant surgeon in the United States Navy; his first sea duty took him to the west coast of Africa, where coast fever invalided him within ten months. His desire for active service was so great that before his health was re-established he obtained orders from the Secretary of the Navy to proceed to head-quarters of the army, then in the City of Mexico, for duty in connection with the collection of data relative to field hospitals and surgical statistics. Here his activity and daring resulted in his being wounded in a guerilla skirmish. Assigned temporarily to a surveying vessel, circumstances soon determined Kane's career and gave full scope to his enthusiastic energies, and insured his future fame. The appeals of Lady Franklin, the recommendations of President Taylor, and the generosity of Henry Grinnell, had culminated in the organization of a search expedition for Franklin in the Arctic regions. It was provided that the vessels should be manned by volunteers from the Navy, and among those offering their services for this mission of humanity none was more importunate than Kane. Persistent efforts brought him orders for this fateful voyage while bathing in the tepid waters of the Gulf of Mexico, and ten days later he sailed from New York for the icy wastes of the North as surgeon of De Haven's flag-ship, the Advance. This search, known in Arctic history as the First Grinnell Expedition, was made under a joint resolution of the Congress of the United States, dated May 2, 1850, "to accept and attach to the Navy two vessels offered by Henry Grinnell, Esq., to be sent to the Arctic seas in search of Sir John Franklin and his companions." Two very small sailing brigs constituted the fleet, the flag-ship Advance, commanded by De Haven, an officer of Antarctic experience under Wilkes, and the Rescue, under Master Griffin; the entire party numbered thirty-three officers and men.