But it would be better that we should reserve any further remarks concerning the archæological relics of Roumania, and also some observations of immediate interest in connection with the Danube, until we have completed a brief account of the water system of the country. Between the 'Iron Gates' and its three embouchures, namely, the Khilia, Sulina, and St. George's mouths, of which only the second is navigable by large vessels, the Danube stretches fora distance of about 650 miles,[23] and receives in its course numerous tributaries, whereof the following are the principal on the Roumanian side. The Pruth is the most important. It forms the boundary between Roumania and Bessarabia (Russia), and is navigable by small grain-carrying vessels. Next in importance historically is the _Sereth_, which divided Moldavia from Wallachia, and the remaining rivers of any moment are the _Oltu_, on which are situated the towns of Rimnic and Slatina; the _Jalomitza_, watering Tirgovistea, one of the ancient capitals, and receiving as an affluent the _Prahova_, which takes its rise near Sinaïa. The last-named is a very interesting river, for in the vicinity of either bank are to be found the petroleum wells or salt mines. Then there is the _Ardges_, which flows past the little city of the same name and the town of Pitesti, and receives the _Dambovitza_, on which the capital, Bucarest, is situated. In these rivers are to be found in their due seasons many species of fish, and as fishing is but little preserved they furnish good sport. The most important kinds used for the table in Roumania are two or three varieties of sturgeon, trout (small but sweet), herrings, salmon, shad, pike, and carp, also perch, roach, barbel, tench, &c. Roumania is not a lake country, and the largest lakes, called Baltas, are found in the plains near the Danube, whilst amongst the inland lakes, which are few in number and importance, that of Balta Alba, in the district of Romnicu Sarat, possesses strong mineral properties, in which chloride of sodium and carbonate and sulphate of soda preponderate. Its waters are used for baths, and are said to cure certain forms of scrofula, rheumatism, neuralgia, and other germane maladies. Besides Balta Alba, Roumania possesses several other sources of mineral waters. [Footnote 20: Paget, vol. ii. p. 44. Dierauer, p. 73, who adds several more disjointed or isolated letters.] [Footnote 21: A dish made from maize.] [Footnote 22: Paget, vol. ii. p. 58. Tocilesco, Plate VII. In the illustrations there given the number of piers varies, but in both cases the intermediate island is shown.] [Footnote 23: The estimates vary from 630 to 650, but these do not make full allowance for all the windings of the river.] III.