1886.] Mineralogy and Petrography. 277 
made up of little globulites, giving rise to a structure very like 
that of many of the obsidians from California and other parts of _ 
the West. The natural glasses in the neighborhood of the 
nepheline basalt of Rossberg, near Darmstadt, are thought by 
Kroustschoff! to owe their origin to the solution in the basalt of 
foreign quartziferous rocks. 
MINERALOGICAL News.—The asterism of Canadian phlogopite 
was noticed by G. Rose,? as early as 1862. He attributed it to 
the intergrowth of foreign crystals, but did not suggest what 
might be their nature. Lacroix? treated some of the Templeton 
mineral with hydrochloric acid and examined the residue. It was . 
found to consist of little hemimorphic crystals of rutile elongated 
in the direction of the vertical axis. In his examination of ba- 
saltic glass from Rossberg, Kroustschoff* discovered a pyroxene 
of a slightly different type from any heretofore described. The 
new type is transparent and of a very light green color. The 
crystals are prismatically developed, and show the forms æ% P 
oP, oP and OP. Very frequently several individuals are 
united by their clino-pinacoids, sometimes by their prismatic 
faces. An analysis of the isolated crystals gave: 
SiO, Al,O, FeO, FeO CaO MgO Na PO 
49.18 2.15 4.96 §.04 = 20,30. - 13.67 1.89 0.30 
——Harringtonite from Ireland has been examined microscopi- \ 
cally.” In polarized light it is resolved into an isotropic mass, in 
which crystals belonging to two distinct species of minerals can - 
be detected. One occurs in little fibrous needles, with longitudi- 
nal extinction and negative refraction; the other is in little frag- 
ments with broken outlines. The former have the optical prop- ` 
erties of mesotype, but are negative. The latter are probably 
Mesotype. Since zeolites are known to have been produced by 
the action of warm waters, Lacroix thinks that Harringtonite 
might be looked upon as a gelatinous mass, which has caught up 
dittle fragments of the minerals that were floating about inthe — 
: Water in which it was formed. At any rate it can no longer be 
b -considered a distinct mineral, i 
i 
, NEw Booxs.—The second edition of Rosenbusch’s “Mikroskop- ` 
_ Asche Physiographie der petrographisch wichtigen Mineralien, 
las recently appeared. This standard’ work is so very well - 
known that the mere mention of the fact of its revision is suffi- — 
-Gent for the purposes of these notes. The advances in the 
_ Methods of microscopical petrography, the improvements in ap- _ 
Bulletin de la Société Minéralogique de France. VIII, p. 62. “a ieee 
- der Berliner Akad. der Wissens., 1862, p. 614; and 1869, p. 344- 
P- 99- Bee 
4 
p. 96. A 
sche Verlagshandlung (E. Koch), Stuttgart, 1885» _ Ae 
