Carte de la Chine dressée d'après les matériaux Chinois les plus authentiques par J. Klaproth avec l'indication des cinq ports ouverts aux Européens. . .

Detailed map of China east of Tibet and including the islands of Tonkin and Taiwan. According to the title the map indicated the five ports open to the European traders according to the Treaty of Nanjing. These five ports, Canton, Shanghai, Ning-pho, Fou-Tcheou, Amoy, Hong Kong and Macao are mentioned in the lower part and underlined in red.
To the left a numbered key (1 - 18) to the different provinces.

Treaty of Nanjing, (Aug. 29, 1842) treaty that ended the first Opium War, the first of the unequal treaties between China and foreign imperialist powers. China paid the British an indemnity, ceded the territory of Hong Kong, and agreed to establish a “fair and reasonable” tariff. British merchants, who had previously been allowed to trade only at Guangzhou (Canton), were now permitted to trade at five “treaty ports” and with whomever they pleased.

Julius Klaproth (1783-1835) devoted his energies in quite early life to the study of Asiatic languages, and published in 1802 his Asiatisches Magazin (Weimar, 1802–1803).
He was in consequence called to St. Petersburg and given an appointment in the academy there. In 1805 he was a member of Count Golovkin's embassy to China.
On his return he was despatched by the academy to the Caucasus on an ethnographical and linguistic exploration (1807–1808), and was afterwards employed for several years in connection with the academy's Oriental publications. In 1812 he moved to Berlin.
In 1815 he settled in Paris, and in 1816 Humboldt procured him from the king of Prussia the title and salary of professor of Asiatic languages and literature, with permission to remain in Paris as long as was requisite for the publication of his works.
He died in Paris on 28 August 1835.

Klaproth was an orientalist or an "Asiatologist," in that he had a good command not only of Chinese, but also Manchu, Mongolian, Sanskrit, Turkish, Arabic, Persian, and even Caucasian languages. His wide range of interests encompassed the study of the development of individual countries in their Asian context. (source Wikipedia)