SCIENTIFIC SUMMARY. 
183 
Herrengi'undite, a new basic Copper sulphate . — This body is described 
by Brezina as occurring in little plates, 1 to 2-5 mm. in diameter, scarcely 
0 "2 mm. in thickness, and having apparently the composition indicated by the 
numbers — 
Sulphuric acid 
, 23-04 
Copper oxide 
.• 57-52 
W ater ..... 
.. 19-44 
• 
100-00 
2*05 lime found in the analysis have been subtracted, as well as the requisite 
amount of sulphuric acid and water to form gypsum with it. The colour of 
the plate-like crystals is dark emerald-green, the hardness, 2*5 : it is almost 
brittle, the cleavage along, oP (001) complete. The axes are, 
a : b : c = 1*8161 : 1 : 2-8004 
Titanomorphite. (Jahrbuck fur Mineralogie, 1879, 897.) — Von Lasaulx 
directs attention to the widely-spread and characteristic product of the 
decomposition of menaccanite, which occurs in rocks, and which he has 
always held to be a lime titanate analogous to perowskite in point of compo- 
sition. He has recently met with it in larger quantities. In a slaty 
amphibole rock from the gneiss of Lampersdorf, near Reichenbach, in Silesia, 
occur rounded nodules of rutile which are covered with a greenish or 
yellowish-white zone of a granulated or fibrous product of decomposition. 
Sufficient of this material was collected for analysis, and found to consist of 
Lime ..... 
. 25-27 
Titanic acid .... 
. 74-32 
Iron protoxide 
. . . Trace 
99-59 
These numbers correspond with the formula, — 
Ca O x 2 Ti 0 2 
which is that of the new mineral. {Jalirb. fur Mineralogie, 1879, 569.) 
A new Barytic Felspar. — Des Cloizeaux found in the collection of the 
Museum (THistoire Naturelle a few fragments of a felspar prism, of unknown 
locality, which are transparent or only translucent, and resemble the albite 
of St. Vincenz, Styria. The two cleavage directions, oP (001) and oo P oo 
(010) form an angle of 86° 37', and the reentering angle of the base was 
found to be 173° 14'. These values approach closely those found for 
labradorite, while the optical characters of the felspar in question more 
closely agree with those of oligoclase and albite. To decide this question, 
the mineral was analysed, and the following results arrived at : 
Silicic acid 
. 55*10 
Alumina . 
. 23-20 ) 
Iron peroxide . 
0-45 ( 
Baryta 
7*30") 
Lime 
1-83 | 
Magnesia . 
0-56 1 
Soda . 
7-45 ( 
Potash 
0*83 | 
Loss by heating 
. . . . 3-72 J 
100-44 
