1868. | Mineralogy. 585 
from the former have been carefully analyzed by Dr. Bertolio. 
Their composition does not differ essentially from that of the 
meteorites which previously fell in this district on the 17th July, 
1840, and on the 2nd February, 1860.* 
A mass of meteoric iron has been found near Nobdenitz, in 
Saxony, and is believed by Dr. Geinitz to be of meteoric origin. 
In some of its characters it much resembles a metallurgical pro- 
duct, but on analysis no carbon was found, whilst nickel was 
detected in considerable quantity. It differs, moreover, from 
terrestrial iron in many of its physical properties. Throughout 
the mass particles of native copper are disseminated, and from this 
is produced the green carbonate of copper which is associated with 
the oxide of iron on the exterior of the meteorite. The following 
is Dr. Fleck’s analysis of the Nobdenitz iron : +— 
Tron eH +e oc os BO°H25 
Copper .. EC 2b 55 {IB 
Nickel -- is ae ae 1-340 
Tin He at fe 1°321 
Cobalt and Chromium ,. .. Traces, 
99-799 
Attention has also been directed to a somewhat similar mags 
of iron found about a year ago at Weissenborn, near Zwickau, in 
Saxony; but it would seem that its meteoric characters are not 
fully established. 
The gorgeous play of iridescent colours exhibited by certain 
polished specimens of Labradorite must have attracted the eye of 
even the least scientific observer. ‘To ascertain the cause of this 
colour and iridescence, Herr Vogelsang has lately subjected some 
specimens to microscopic examination. Many sections showed a 
great number of minute disseminated crystals, which he calls 
“ Microliths.” These differ considerably in form and colour, and 
it would be difficult in all cases to say what they really are. Some, 
however, appear to be diallage, and others magnetic iron ore. The 
golden reflections exhibited by some labradorites are supposed to 
result from the total reflection of light incident upon these micro- 
ths; whilst the blue colour characteristic of other specimens is 
apparently due, not to the embedded crystals, since it is equally 
displayed in their absence, but to a phenomenon of polarization 
resulting from the refraction of light from one lamella to another. 
Dr. Scharff has lately studied the characters of that unsatis- 
factory species, Sericite.§ It occurs abundantly in the schists of 
* Bullettino Meteorologico dell’ Osservatorio del R, Collego Carlo Alberti in 
Monealieri. 31 March, 30 April, 30 June, 1868, 
ta* Neues Jahrbuch.’ 1868. Heft IV., p. 461. 
{ ‘ Archives Néerlandaises,’ 1868, IIL., p. 32. 
§ ‘Neues Jahrbuch,’ Heft IIL, p. 309. 
