In length, and communicates with the Little Belt, and at the junction of the main line of railway from Woyens with three vicinal lines.
Of the tri-substitution derivatives, 1.2.3.-compounds are known as " adjacent " or " vicinal " (v), the 1.2.4 as " asymmetrical " (as), the 1.3.5 as " symmetrical " (s), of the tetrasubstitution derivatives, 220.127.116.11-compounds are known as " adjacent," 18.104.22.168 as " asymmetrical," and 22.214.171.124 as " symmetrical."
The skeletons of these types are (the carbon atoms are omitted for brevity): We have previously referred to the condensation of heterocyclic ring systems containing two vicinal carbon atoms with benzene, naphthalene and other nuclei.
One or two benzene nuclei may suffer condensation with the furfurane, thiophene and pyrrol rings, the common carbon atoms being vicinal to the hetero-atom.
Of the tri-derivatives the symmetrical compounds boil at the lowest temperature, the asymmetric next, and the vicinal at the highest.
It has served as a basis for a Carte de la France, published by the Service Vicinal on a scale of i: 100,00°, in 59 6 sheets, and of a general map prepared by the ministere des travaux publics on a scale of I: 200,000 in 80 sheets.
The town perhaps occupies the site of the ancient Nidus or Nidum of the Romans on the Julia Maritima from which a vicinal road branched off here for Brecon.