They are traversed by three principal valleys: (I) that of the Anio, now called Teverone, which descends from above Subiaco to Tivoli, where it enters the plain of the Campagna; (2) that of the Trerus (Sacco), which has its source below Palestrina (Praeneste), and flows through a comparatively broad valley that separates the main mass of the Apennines from the Volscian mountains or Monti Lepini, till it joins the Liris below Ceprano; (3) that of the Liris (Garigliano), which enters the confines of New Latium about 20 m.
As Admiralty Sound and Lake Fagnano bound the Cordillera to the north in Tierra del Fuego, so at the eastern side of the Cordillera in the southernmost part of the continent there is a longitudinal depression which separates the Andes from some independent ridges pertaining to a secondary parallel broken chain called the pre-Cordillera.
The maritime chain separates into two branches, which run parallel to each other for 100 m., enclosing the remarkable ravine of Callejon de Huaylas - the eastern or main branch being known as the Cordillera Nevada and the western as the Cordillera Negra.
The Bug, another right-hand tributary of the Vistula, describes a wide curve concentric with those of the middle Vistula and the Narew, and separates the Polish governments of Lublin and Siedlce from the Russian governments of Volhynia and Grodno.
Last is the Altai, near the 50th parallel, rising to 10,000 or 12,000 ft., which separates the waters of the great rivers of western Siberia from those that collect into the lakes of northwest Mongolia, Dzungaria and Kalka.
In this feature, and in its almost universal conservation of the final vowels e, i, u (o), Castiian comes very near Italian, while it separates from it and approaches the Gallo-Roman by its modification of the consonants.
South of the Gomal it separates the interests of Afghanistan from those of Baluchistan, which here adjoins the North-West Frontier Province.
In most cases the actual boundary consists of rivers or lakes, the Ottawa to the north-east, the St Lawrence and its chain of lakes and rivers to the south as far as Pigeon river, which separates Ontario from Minnesota.
Each singular kind presents itself as a limit separating two kinds of inferior singularity; the cuspidal separates the crunodal and the acnodal, and these last separate from each other the complex and the simplex.
The salt separates from solutions containing hydrofluoric acid in large plates, which are greenish yellow in colour.