20 PETBIFACTIONS AND THEIR TEACHINGS. CHAP. I. 



yttria, and phosphates of alumina, as wavellite, arurite, the calaite or 

 real turquois from Persia, 1 &c. 



[57 A.] Phosphates combined with chlorides. Pyromorphite ; arse- 

 niates of lead, &c. 



[57 B.] Phosphate of lime combined with chloride of calcium. Bare 

 crystallizations of apatite. Chloro-carbonate of lead. The unique suite 

 of crystals is from Cromford Level, near Matlock Dale, Derbyshire. 



8. [4.] Native arsenic, with nickel and with cobalt. In the opposite 

 half of this case, substances belonging to the orders carbon and selenium. 

 Diamonds ; several illustrations of the various crystalline forms of this 

 pure state of carbon ; diamonds imbedded in siliceous breccia, in com- 

 pact brown ironstone ; and a specimen of the alluvial rock called cascal- 

 hao, in which diamonds occur in the East Indies and the Brazils. An- 

 thracite. Graphite. Seleniurets of lead, copper, mercury, cobalt, &c. 

 Sulphur from the Lipari Isles. A medallion in selenium of Berzelius, 

 the discoverer of this metal. 



9. [56.] Arsenious acid, and arseniates of lime, iron, copper, cobalt, 

 nickel, &q. 



10. [5.] Splendid crystallisations of sulphur from La Catolica in Sicily. 

 These are succeeded by the sulphurets, which occupy half of this, and 

 seven of the next following table cases, according to the museum nota- 

 tion. Sulphuret of manganese, zinc or blend, &c. 



11. [55.] Sulphates of magnesia, zinc, iron, copper, lead, &c. Sulphate 

 of uranium, oxide or johannite, very rare, from Bohemia. Sulphates of 

 alumina. Websterite from Sussex and Halle. Beautiful series of examples 

 of lazurite or lapis lazuli. 



12. [6.] Sulphurets of iron, or iron pyrites. Sulphuret of cobalt, of 

 nickel, of cadmium, &c. 



1 The oriental turquois is an hydrate of aluminum coloured by oxide 

 of copper and iron ; it is found in amorphous masses in alluvial clay, 

 and in irregular veins in flinty slate, in Persia and Siberia. The com- 

 mon or accidental turquois is fossil ivory or bone stained by blue phos- 

 phate of iron or carbonate of copper. 



