538 Progress in Science. [October, 



Having had his attention directed to Wagnerite, by the study of Kjerulfin, 

 Von Kobell has undertaken a new analysis of the old phosphate. From this 

 recent examination of Wagnerite its formula seems to be thus represented : — 

 2( 3 MgO.P 2 5 ) + (fNa,iCaJF 4 . 



A new mineral, belonging to the Pinite group, has been described by 

 Laspeyres, of Aix-la-Chapelle, under the name of Hygrophyllite. This name 

 refers to the curious behaviour of the mineral when brought in contadt with 

 water or with steam. Placed in water, the mineral — which is ordinarily of a 

 greenish tint — immediately becomes white, and exfoliates in very fine scales, 

 which peel off, layer after layer, until the entire mineral is disintegrated, and 

 a whitish-grey finely-divided plastic mass is obtained, which, under the micro- 

 scope, is seen to be made up of very delicate scales. In many other liquids, 

 such as alcohol, ether, hydrochloric and nitric acids, the mineral retains its 

 coherence. 



Some '• Mineralogische Mittheilungen " have been communicated by Dr. 

 Wibel, of Hamburg, to Leonhard and Geinitz's "Jahrbuch." One of these 

 communications describes the occurrence of the rare mineral, lime-uranite 

 (autunite), in the so-called Portuguese phosphorite. The presence of a 

 mineral containing uranium in a substance whose origin is so often referred to 

 organic agency is not without its interest. The author has analysed a sample 

 of gold from Vancouver Island, with the following results: — Golr!, gi-86; 

 silver, 663 : copper, roo ; iron, 0*51. A third subject discussed by .Wibel is 

 the composition and formation of blue carbonate of copper (azuritej. His 

 analysis of a Siberian specimen gave — Cupric oxide, 69-66 ; carbonic anhy- 

 dride, 24*26 ; water, 608. 



It is proposed by Von Kobell to change the name of the mineral called 

 Montcbrasitc by Des Cloiseaux into that of Hebronite, the mineral having long 

 been known from Hebron, in Maine, U.S. 



The rare mineral called jfordaniie, from the Binnenthal, has been lately 

 studied by Sipocz, whose analysis points to the formula As 2 Pb 4 S 7 . 1 he same 

 chemist also publishes analyses of a Hungarian Bustamite and an East-Indian 

 potash-mica. 



So much discrepancy may. be observed in the analyses of the oxychloride of 

 copper called Atacamite that we are glad to see that the mineral has been 

 lately re-examined by E. Ludwig. His analyses of some fine crystals from 

 Wallaroo, in South Australia, give results indicated by the formula 

 CU2CIO3H3. The author believes the hydrogen to be essential to the consti- 

 tution of the molecule of Atacamite, and that it exists in the form of hydroxyl. 

 He constructs the following constitutional formula, making the atom of copper 

 tetratomic : — 



Cu(OH)Cl 



II 

 Cu(OH) 2 . 



The author's analysis of Brochantite also points to copper as a tetrad. 



Atacamite has likewise been lately studied by Tschermak, who has specially 

 directed his attention to the alteration by which this mineral can be trans- 

 formed into malachite, some fine pseudomorphs illustrating this change having 

 been obtained from the Siberian copper-mines. 



Artificial crystals of Atacamite have recently been obtained by Friedel, 

 whose process renders it probable that some natural forms of this oxychloride 

 may have been produced by the action of ferric chloride on cupric or cuprous 

 oxides. These results were obtained during the author's examination of a 

 new mineral, Delafossite, which is a combination of the oxide of iron and 

 copper, corresponding to Fe 2 3 .Cu 2 0, or perhaps to the simpler expression 

 FeO.CuO. 



In some mineralogical notes on the Far West, Prof. Silliman puts on record 

 the existence of Enargite in Southern Utah ; and of bismuthine, wulfenite, 

 orpiment, and realgar, from the same territory. He also describes a new borate 

 of lime from Nevada, under the name of Priceite. 



