314 Geological Society : — 



The speaker stated that the foregoing facts clearly pointed out 

 that vanadium, hitherto standing in no definite relation to other ele- 

 ments, must be regarded as a member of the well-known Trivalent 

 or Triad class of elementary substances, comprising nitrogen, phos- 

 phorus, boron, arsenic, antimony, and bismuth. 



It is true that we are still but imperfectly acquainted with many 

 of the characters of vanadium ; but the more its nature is stu died, the 

 more points of family resemblance will be discovered, and the more 

 close will the ties be found which bind it to the great Triad family. 



The following tabular statement of the compounds of the most 

 important members of this group clearly shows their common rela- 

 tions : — 



Trivalent Group of Elements. 



Nitrogen. Phosphorus. Vanadium. Arsenic. Antimony. 



N = 14 P=31 V=51-3 As = 75 Sb = 122 



Trihydrides NH 3 PH 3 As H 3 Sb H 3 



Trichlorides !NC1 3 (?) PCI 3 VC1 3 As CI 3 SbCl 3 



Pentachlorides ... — PCI 5 — — Sb CP 



Oxychlorides ... — POC1 3 VOC1 3 — — 



Monoxides N 2 — — — — 



Dioxides N 2 2 — V 2 2 — — 



Trioxides N 2 3 P 2 3 V 2 3 As 2 3 Sb 2 3 



Tetroxides N 2 4 — V 2 ^ — Sb 2 4 



Pentoxides N 2 5 P 2 5 V 2 O 5 As 2 5 Sb 2 O 5 



In conclusion, the speaker remarked that vanadium was the fourth 

 substance, supposed by its discoverer to be a metal, which had in 

 recent years been shown to be a compound body. 



Titanium. Uranium. Niobium. Vanadium. 



Wollaston, 1823. Klaproth, 1789. J Hatchett, 1801. f Sefstrom and 



Wohler, 1849. Peligot, 1849. \ Rose, 1842-64. \ Berzelius, 1831. 



Marignac, 1865. 



GEOLOGICAL SOCIETY. 



[Continued from p. 155.] 



January 22nd, 1868.— Warington W. Smyth, M.A., F.R.S., 



President, in the Chair. 

 The following communications were read : — 

 1. " On the Speeton Clay." By John W. Judd, Esq., F.G.S. 

 In tracing the history of discovery in connexion with this forma- 

 tion, the following epochs were pointed out by the author : — (1) the 

 separation of the Cretaceous from the Kimmeridge beds by Prof. 

 Phillips (1829) ; (2) the reference of the former to the Neocomian 

 formation by MM. Agassiz, Godwin-Austen, Romer, and others 

 (1838 &c.) ; and (3) the recognition of Portlandian beds in the 

 series by Mr. Leckenby (1864). 



Mr. Judd then proceeded to give a description of the unique 

 cliff-section exposed at Speeton, which is unfortunately greatly 

 complicated by faults and contortions, and much obscured by drift, 

 landslips, and mining workings. 



