SCIENTIFIC JOURNALS AND ARTICLES
under the formula xRO~yMnO;zH,O, of which the cobalt bearing variety, asbolite, has an important economic value as a cobalt ore. Rancieite is a calcium-bearing variety of psilomelane. Under anhydrous sulphates and chromates are descriptions of mascagnite, thenardite and metathenardite, which is the name given to a polymorphic form of Na,SO, stable above 235' and differing in its crystalline and optical properties from thenardite. I t was found at a secondary fumarole (temp. 500-590") of Mt.
... 00-590") of Mt. Pelee and had evidently formed from fusion. There are then described glauberite, anhydrite, the barite group with many photographs and crystal drawings, the alunite group in which an occurrence of natroalunite from Martinique may be noted, lanarkite, brochantite and linarite. Caledonite and leadhillite are the two sulfates with carbonates. The list of hydrous sulphates is an extensive one and includes mirabilite, gypsum (nearly 50 pages) and most of the vitriols, namely, epsomite, goslarite, morenosite, melanterite, pisanite, boothite, bieberite and chalcanthite. Further alunogen, connellite, coquimbite, fibroferrite, aluminite with which fel'stibanyite and paraluminite may be identical, being only aluminite in a somewhat altered condition. Apatelite (Fe, Al),(OH),-SO4,+ H,O is a definite mineral species, its composition as here given being deduced from a new analysis of original material, the results obtained differing very much from the original analysis.' The remaining sulphates described are copiapite, glockerite, polyhalite, kalinite, halotrichite, pickeringite, metavoltite, roemerite, botryogen and cyanotrichite. Of the molybdates and tungstates there are wulfenite, scheelite and the wolframite group composed of ferberite FeWO" wolframite (Fe, Mn)W04 and hiibnerite MnWO" though Lacroix states that the analyses of ferberite show an excess of FeO. Molybdite from Corsica showed qualitatively the presence of iron and water. The aluminates, ferrites, chrom-lThe composition of this and several related minerals badly needs revision. From t h e data now at hand, apaslite, raimondite, cyprussite and possibly several others are probably identical (W. T. S.).