$40 Vanadiate of Lead^ a Nei& Mineral Species, 



pronounced by him to be an arseniate of lead. Under this name 

 it is to be found in several collections. 



■ Externally, it has much resemblance to arseniate of lead, 

 from some varieties of which it is not easily distinguished. It 

 resembles also some molybdates. It is opaque, of a straw yellow, 

 or brownish yellow colour ; brittle ; scratched by the knife, 

 giving a white streak ; its cross fracture is slightly conchoidal ; 

 externally it is dull, or has only a faint lustre ; the lustre of 

 broken surfaces is resinous. Its specific gravity is 7.23. It 

 occurs in six-sided, but more frequently in four-sided, truncated, 

 nearly rectangular prisms. The prisms are longitudinally striated, 

 sometimes occurring singly, but generally grouped together into 

 globular forms. When the individuals are exceedingly minute, 

 they constitute perfectly round striated mamillaj of various 

 sizes, from that of a pin's head to that of a pea. When the 

 individuals are larger, the prisms appear superimposed longitudi- 

 nally, overlying one another in the direction of one of the 

 longitudinal diagonals of the underlying prism ; so that the edge 

 of the superincumbent crystal nearly coincides with that diagonal. 



Before the blowpipe in a pair of forceps it decrepitates and 

 fuses, retaining its yellow colour ; but it soon changes entirely 

 into a steel grey porous mass, which, with soda and charcoal, 

 gives immediately globules of lead. With the other fluxes it 

 shews the same reaction as chromium. 



It is soluble in the nitric and muriatic acids, giving, at first, a 

 brown solution, which, by standing, or by dilution, becomes a 

 beautiful green. Treated with dilute nitric acid, the lead is first 

 dissolved out, and the vanadic acid separates in beautiful red 

 scales, which are afterwards taken into solution. 



This mineral is found at W^anloekhead, in the lead veins, 

 associated with galena, calamine, and peroxide of manganese. 

 The quantity hitherto brought to the market is small ; but, since 

 its value is now di-scovered, it is to be hoped that a more 

 abundant supply may be procured.. 

 \ Partobelloy 2Ut May, 1831. 



^AirtJ^III.—- ^ Sketch of the Distribution of Animals and Plants 

 in the Southwestern extremity of Great Britain, By J. F. 

 Kingston, Esq.* 



f^'Ab'^fesAt sketch of the southwestern extremity of Great 

 Britain, as respects its physical characters, the number, and 



* We regret that the author has not increased the valne of this paper by giving a 

 fiiHer list of the species of animals ; as the object of instituting a comparison with other 

 districts can only be successfully accomplished upon such data. It would also have 

 been desirable that the modern nomenclature had been adopted. The species of the 

 botanical department Mr Kingston has already enumerated in conjunction with the 

 'Rer. J. P. Jones, in the Flora Devoniensis. — Editor. 



