At Macau he spent some eighteen months in the Lazarist seminary, preparing himself for the regular work of a missionary. Having acquired some command of the Chinese language, and modified his personal appearance and dress in accordance with Chinese taste, he started from Canton (Guangzhou).
He at first superintended a Christian mission in the southern provinces, and then passing to Peking (Beijing), where he perfected his knowledge of the language, eventually settled in the Valley of Black Waters or He Shuy, a little to the north of the capital, and just within the borders of Mongolia. There, beyond the Great Wall, a large but scattered population of native Christians had found a refuge from the persecutions of KiaKing, to be united half a century later in a vast but vague apostolic vicariate.
The assiduity with which Huc devoted himself to the study of the dialects and customs of the Tatars, for whom at the cost of much labour he translated various religious works, was an admirable preparation for undertaking in 1844, at the instigation of the vicar apostolic of Mongolia, an expedition whose object was to dissipate the obscurity which hung over the country and habits of the Tibetans. September of that year found the missionary at Dolon Nor occupied with the final arrangements for his journey, and shortly afterwards, accompanied by his fellow-Lazarist, Joseph Gabet, and a young Tibetan priest who had embraced Christianity, he set out.
To escape attention the little party assumed the dress of lamas or priests. Crossing the Hwang-ho, they advanced into the terrible sandy tract known as the Ordos Desert. After suffering dreadfully from want of water and fuel they entered Kansu, having recrossed the flooded Hwang-ho, but it was not till January 1845 that they reached Tang-Kiul on the boundary. Rather than encounter alone the horrors of a four months journey to Lhasa they resolved to wait for eight months still the arrival of a Tibetan embassy on its return from Peking. Under an intelligent teacher they meanwhile studied the Tibetan language and Buddhist literature, and during three months of their stay they resided in the famous Kunbum Lamasery, which was reported to accommodate 4,000 persons. Towards the end of September they joined the returning embassy, which comprised 2,000 men and 3,700 animals.
Crossing the deserts of Koko Nor, they passed the great lake of that name, with its island of contemplative lamas, and, following a difficult and tortuous track across snow-covered mountains, they at, last entered Lhasa on the January 29, 1846. Favourably received by the regent, they opened a little chapel, and were in a fair way to establish an important mission, when the Chinese ambassador interfered and had the two missionaries conveyed back to Canton, where they arrived in October of the same year.
For nearly three years Huc remained at Canton, but Gabet, returning to Europe, proceeded thence to Rio de Janeiro, and died there shortly afterwards. Huc returned to Europe in shattered health in 1852, visiting India, Egypt and Palestine on his way, and, after a prolonged residence in Paris, died on March 31, 1860.
His writings comprise, besides numerous letters and memoirs in the Annales de la propagation de la foi, the famous Souvenirs d'un voyage dans la Tartarie, le Thibet, et la Chine pendant les années 1844—1846 (2 vols., Paris, 1850; Eng- trans. by W. Hazlitt, 1851, abbreviated by M. Jones, London, 1867); its supplement, crowned by the Academy, entitled L'Empire chinois (2 vols., Paris, 1854; Eng. trans., London, 1859); and an elaborate historical work, Le Christianisme en Chine, &c. (4 vols., Paris, 1857—1858; Eng. trans., London, 1857—1858).
These works are written in a lucid, racy, picturesque style, which secured for them an unusual degree of popularity. The Souvenirs is a narrative of a remarkable feat of travel, and contains passages of so singular a character as in the absence of corroborative testimony to stir up a feeling of incredulity. That Huc was suspected unjustly was amply proved by later research. But he was by no means a practical geographer, and the record of his travels loses greatly in value from the want of precise scientific data.
See, for information specially relating to the whole subject, the Abbé Desgodin's Mission du Thibet de ~ a 1870 (Verdun, 1872) and Account of the Pundit's Journey in Great Tibet, in the Royal Geographical Society's Journal for 1877.