246 Geological Society. 



metric system. The analysis of the platinum-salt led to the formula 



C u II 34 PA S Pt 2 Cl 6 =r(C 2 H 4 )" £» **«>■* Tci 2 ,2PtCl, 

 L (C 2 H 5 ) 3 AsJ 



The phospharsonium-compounds, and more especially the hydrated 

 oxide of the series, are far less stable than the corresponding terms 

 of the diphosphonium- and even of the phosphammonium-series. If 

 the product of the action of triethylarsine upon the brominated bro- 

 mide be boiled with oxide of silver instead of being ti'eated in the 

 cold, not a trace of the phospharsonium-compound is obtained. 

 The caustic solution which is formed, when saturated with hydro- 

 chloric acid and precipitated with dichloride of platinum, furnishes 

 only the rather soluble octahedral crystals of the oxethylated triethyl- 

 phosphonium-platinum-salt. The nature of this transformation is 

 clearly exhibited when a solution of the dioxide of phospharsonium 

 is submitted to ebullition. Immediately the clear solution is rendered 

 turbid from separated triethylarsine, which becomes perceptible, 

 moreover, by its powerful odour, the liquid then containing the 

 oxide of the oxethylated triethylphosphonium, 

 [(C 3 H 4 )"(C 2 H 5 ) 6 PAs]"| _ [(C 2 H 5 0)(C 2 H 5 ) 3 PJ1 o 



II 2 J u 2 -( C 2H 3 ) 3 As+ h J 



GEOLOGICAL SOCIETY. 



[Continued from p. 1G6.] 



May 22, 1861. — Leonard Horner, Esq., President, in the Chair. 



The following communications were read : — 



1 "On the Geology of a part of Western Australia." By 

 F. T. Gregory, Esq. 



The author first described the granitic and gneissose tract of the 

 elevated table-land ranging northwards from Cape Entrecasteaux 

 and comprising the Darling Downs. The igneous rocks and quartz- 

 dykes were next referred to, and also the clays, sandstones, and 

 conglomerates capping the table-land. Carboniferous, cretaceous, 

 and pleistocene rocks were also alluded to ; and some evidences of 

 the recent elevation of the coast were brought forward. Besides 

 specimens of rocks and minerals, the following fossils from Western 

 Australia were exhibited : Carboniferous fossils and cannel-coal from 

 the Irvin River; Fossils of secondary age {Trigonice, Ammonites, and 

 fossil wood) from the Moresby Range ; fossil wood from the Stirling 

 Range and from the Upper Murchison River ; Ventriculites in flint 

 from Gingin, and Brown-coal from the Fitzgerald River. The 

 author's views of the geology of the district were shown by an ori- 

 ginal map and accompanying sections. 



2. "On the Zones of the Lower Lias and the Avicula contorta 

 Zone." By Charles Moore, Esq., F.G.S. 



Referring to a paper on this subject, by Dr. Wright, which ap- 

 peared in the sixteenth volume of the Society's Journal, the author 

 stated that details of the section at Beer-Crowcombe (near Ilminstcr) 

 in Somersetshire are now more fully known than they were when 



