Reviews—Professor Rosenbusch’s T0th Birthday. 365 
Prof. A. Osann (Freiburg-i.-B.), ‘‘On some Alkali-rocks from Spain,” 
describes three rock-types. (1) A verite from Fortuna in the province 
of Murcia, previously described by Ramon Adan de Yarza as 
‘fortunite.’ It is a glassy facies of (2) a rock termed by Yarza 
a trachyte, but which Osann proposes to call ‘fortunite.’ This 
fortunite (Osann) exhibits microscopically phenocrysts of almost 
colourless rhombic pyroxene, which is the only constituent to occur 
in two generations. It is accompanied in the groundmass by 
monoclinic pyroxene allied to diopside, phlogopite (mica), sanidine, 
apatite, ilmenite, and a not inconsiderable amount of glassy base. 
(3) The parent rock of the Jumilla apatites, which occur in veins 
traversing the voleanie rock., The rock is allied to the orendites of 
Whitman Cross, and Osann proposes to call it ‘jumillite.’ It is the 
first rock rich in leucite to be described as occurring in Spain. 
C. Palache (Harvard University), ‘‘On Octahedrite, Brookite, and 
Titanite from Somerville, Massachusetts, U.S.A.,”* describes the 
occurrence of these titanium compounds in veins in diabase, from the 
alteration of the ilmenite in which he holds that they are derived. 
Twin structure [ with (101) as twin plane | in octahedrite is recognized 
for the first time, and the alteration of brookite to sagenitic aggregates 
of rutile is recorded. 
Dr. H. Preiswerk (Bale), ‘‘ Malchites and Vintlites in the Strona- 
and Sesia-gneiss (Piedmont),’’ describes two dykes of hornblende- 
malchite and one of mica-malchite at Lago Mergozzo, near Lag» 
Maggiore, a dyke of diorite-porphyrite in Valle Canobbina and a 
yintlite (diorite-porphyrite) from a pass east of Gaby in Val Gressoney. 
Prof. G. Steinmann (Freiburg-1.-B.), ‘‘ The Origin of the Copper-ore 
Deposits of Corocoro and allied occurrences in Bolivia.” The deposits 
described are limited to the inter-Andean plateau of the Bolivian 
Cordillera and occur in the Cretaceous Puca sandstone. The copper 
oceurs chiefly in the metallic state. Prof. Stemmann regards it as 
a subsequent deposit. He believes it was contained in a solution in 
which sulphuretted hydrogen, sulphurous acid, and perhaps also carbon 
dioxide were the gaseous constituents. In order to obtain from such 
a solution metallic copper oxidising substances are requisite, and such 
are everywhere present in the sandstone, as iron oxide or hydrates. 
The sulphides of the solution will be oxidised, the sandstone will be 
bleached (as it is around the copper), the metal will be set free, 
and gypsum (usually present in the deposits) will be formed. 
Prof. Steimmann believes the ultimate source of the copper to be in the 
Tertiary Andes granites, diorites, and hypocrystalline porphyritic 
igneous rocks. 
Dr. Th. Nicolau (Jassy), ‘‘ The Aragonite of Sarul Dornei,” describes 
needle-shaped crystals found in cavities of a sandy marl in Moldavia. 
Dr. L. Finckh (Berlin), ‘‘ The Rhomb-porphyries of Kilimanjaro,” 
describes the rocks of Kilimanjaro previously described under other 
names by Prof. Bonney,! J. S. Hyland,? and Tenne.* They agree in 
1 Min. Mag., No. 32 (1886), pp. 10-12. 
* Tschermak’s Min. & Pet. Mitt., vol. x (1888), p. 203. 
3 H. Meyer: ‘‘ Ostafrikanische Gletscherfahrten,’’ Leipzig, 1890, p. 305. 
