1889.] Mineralogy and Petrography. 1093 
ous and staiirolitic gneiss. The andalusite is often an alterative pro- 
duct of the corundum. Cyanite, rhgetzite and margarite pseudomorphs 
of andalusite are quite common in the rock. — Von Eterlein 2« describes 
a new occurrence of calcite in the Floitenthal, Tyrol. The crystals 
are implanted in a granitic muscovite gneiss. Those containing the 
basal plane have this face marked by three "systems of striations, running 
parallel to the three edges oR, a, R. They are thought to be due to 
etching. A bed of sulphur in the volcanic island Saba in the W. Indies 
contains crystals of this substance, very rich in crystal planes. Twenty- 
three forms have been detected upon them by Molengraff, ^i and of 
these four are new, viz. 3?^, 2P, 3P and P3. Two crystals of 
neochrysolite from the 1631 lava stream of Vesuvius, the one with a 
tabular habit, and the other columnar, have been carefully measured by 
Scacchi, 22 ^yho regards the mineral as very similar in all its properties 
to fayalite. — Analyses of dufrenite"^^ from Cornwall correspond to the 
formula 3Fe,03.Fe0.2P,05.6H30, and not to 2¥tf),, ¥,0,, 3H,0 as 
is usually supposed. Warrenite^* is the name proposed for the sulph- 
antimonate described by Eakins some time ago. 
Miscellaneous.— HwicYnng?,^^ records the discovery of a little crystal 
of jvillemite in a slag obtained during the fusion of lead dross. The 
slag contains ly^ per cent, of lead, and from 12-15 per cent, of ZnO, 
and it consists of fayalite, zinc, spinel and magnetite, with but a trace 
of amorphous base. A second run of the same furnace yielded no 
willemite. The slag in this case contained 5 per cent, of lead, and 
was in large part glassy, and in it were idiomorphic crystals of fayalite. 
The observations are interesting, also showing the effects produced in 
the structure of the cooled magma by the slight differences in the per- 
centage of lead. Crystals of cuprite and cerussite are described by 
Fletcher "^ as resulting from the slow alteration of old Roman coins 
buried at Chester, England. The crystals line the cavities between 
adjacent coins, and are supposed to be due to the action of circulating 
alkaline waters on the metals in them. 
»» Zetts./ur Kryst., XIV., p. 28al 
2» Zeits./ur Kryst., XIV.. p. 43. 
" Zeits./ur Kryst., XIV., p. 293. 
** Kinch : Miner. Magazine, Oct., 1888, p. 112, 
"^^Amer. Jour. Set., Jan., 1890. p. 75- 
"^ Geol. Mag., ]2in., 1890. p. 31. 
"^ Miner. Magazine, Dec, 1887. p. 87. 
