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extent of one-half its weight of nickel-iron ; the matrix is colourless and 
transparent. Tschermak, who has examined the specimen sent to the Vienna 
collection, finds it to closely resemble the stones which fell in such numbers 
at Pultusk in January 1868. The crust in the former case, however, is 
thicker. A careful examination of a section of the Hungen stone enabled 
Tschermak to detect the presence of particles of nickel-iron, some 1*5 mm. in 
diameter, as well as granules of magnetic pyrites. The mass of the stone con- 
tained abundance of chondra, some opaque and lustreless, consisting apparently 
of chromite or picotite, while the transparent ingredients are of three kinds : 
one the crystalline characters and optical orientation of which identified it 
with olivine ; a second in granular fragments which appeared to consist of 
bronzite ; and a third the angular particles of which had a finely foliated 
texture, resembling diallage or augite. — Jahrbuch fur Minet'alogie , 1878, 
p. 411. 
Sodium Chloride. — Bertrand has described crystals of salt from the Soda 
Lakes of Egypt, some 1 cm. in diameter, which were either octohedra or 
octohedra combined with the dodecahedron and the cube. The majority of 
them were not transparent, and had a grey colour. Sodium chloride has been 
obtained in octohedra of very small size, and without any other planes, by 
crystallization from a concentrated solution saturated with sodium carbonate. 
— Zeitschrift fur Krystcdl. und Mineralogie , 1878, p. 199. 
The Rocks of the Island of Vulcano. — Cossa finds that the alum of this 
island contains a relatively large amount of the sulphates of caesium, 
rubidium, thallium, and lithium, all of which salts are probably present in 
the form of alums ; and it is stated by him to stand second only to the rare 
pollux of Elba as material for the preparation of caesium compounds. The 
rocks overlying the alum beds appear to have furnished the caesium and 
rubidium, which are present in them in the form of silicates. These have 
subsequently been converted into alums by the action of acid vapours. A 
reddish porous crystalline mass which collects on the floor of the crater con- 
tained considerable quantities of sulphates of lithium, caesium, and thallium, 
only traces of rubidium and potassium, and, in addition, boracic acid, am- 
monium chloride, arsenic sulphide, and selenium sulphide. Cossa recom- 
mends antimony chloride for the separation of caesium and rubidium, and 
states that Stolba’s method with tin chloride did not yield satisfactory 
results in his hands. A gas escaping from a mineral water which bubbled 
forth near the crater consisted of carbonic acid, 79 vols. ; nitrogen, 20-5 
vols. ; and oxygen, 0*5 vol. in 100 vols. — Ber. deut. Chem. GeseLl. 1878, 
xi. p. 811. 
The Miner alogische Mittheilungen , edited by Prof. Tschermak, since the 
issue of the first part in 1871, and published as a supplement of the “ Jahr- 
buch der K.K. Geolog. Iteichsanstalt,” has ceased to appear ; and in its place 
Prof. Tschermak will edit “ Mineralogische und Petrographische Mittheilun- 
gen,” which will be published independently, six parts to be issued each year. 
Two parts have already appeared. In addition to original articles they con- 
tain notices of memoirs which have appeared in other scientific journals. 
Rseudohrookite and Szab&ite. — Koch describes, under the name of pseudo- 
brookite, a rhombic mineral from the Aranyer Berg, in Siebenbiirgen, 
having the composition : — 
