The disease in 1817 appeared on the Delta of the Ganges, and gradually extending its influence, swept over various countries with terrible severity. Having here acquired its full development, and manifesting an indomitable determination to itinerate, it starts upon its lethean errand, and soon shows a capacity and power to overcome every obstacle opposed to its progress, and to pursue its course unchecked and even unretarded by any natural or artificial barrier. It soon traversed India, and in the succeeding season spread over adjacent countries, visiting in 1818 the Indian Peninsula, the Burmese Empire, the Kingdom of Aracan, and the Peninsula of Malacca. In 1819 it reached Sumatra, Singapore, and various other islands situated along the coast on either border of this vast peninsula. During the year 1820, pursuing steadily its progress eastward, it reached Tonquin, Southern China, Canton, the Philippine, and numerous other places and islands in that direction. In 1821 it visited Java--the place of its earlier nativity--Madura, Borneo, and many other places in the Indian Archipelago. During the years 1822, 1823 and 1824, it continued to spread over the vast and populous regions of Central and Northern China and the numerous islands upon the coast, and in 1827 prevailed in Chinese Tartary, leaving few places in all these different countries on the continent, or even on the islands bordering on the eastern coast, unscathed by its terrible ravages and depopulating influence. During the same period, its progress westward has been uninterrupted, and attended with results no less remarkable. It has baffled all attempts to check or even retard its onward course, or mitigate its appalling effects. In July, 1821, it had reached Muscat in Arabia, and thence extended its influence to the populous cities and villages along the Persian Gulf. During the same season it appeared in Persia, and continued to ravage the principal cities and towns of that empire for four successive years. At Bassorah and Bagdad it broke out in July, 1821, and thence extended its desolating influence westward to the Red and Mediterranean Seas, carrying off vast numbers of the inhabitants of the populous cities of Mesopotamia, Syria, and Judea. In 1822 it prevailed among the nomadic and Tartar tribes in Central Asia and in the northern Persian Provinces, and in 1823 broke out on the Georgian frontiers of Russia, at Orenburg on the River Ural, and at Astrachan on the Volga. Here its western course was apparently interrupted. There was, for a short period, an interval of complete immunity from its presence. Along the border of the Russian Provinces the disease had entirely disappeared, and seemed inclined to retrace its course and return to the home of its birth. But the fond anticipations of Europeans were disappointed; the destroyer was not to be arrested and turned back in his progress over the earth; his march was onward, his demands imperative.