62 General Notes. [ January, 
muthite, from Lake City, Col., gave results corresponding to 
(Ag; Pb) S, Bi, S Cosalite is a sulpho-bismuthite of the formula 
2 (Pb Ag») S, Big S; from Cosala, Mexico. In the Gladiator mine, 
Ouray county, Col., a compact mineral occurs in small irregular 
masses. An analysis shows it to be cosalite with part of the sil- 
ver replaced by Cu, having the formula 2 (Pb Ag, Cue) S, Big Sy. 
Schirmerite, beegerite, tetrahedrite, sylvanite and polybasite from 
Colorado, and arsenopyrite and scorodite from Alabama are the 
other sulphur salts examined. Ilmenite from Carter’s mine, N.C, 
topaz from Stoneham, Me., muscovite pseudomorphs after neph- 
eline-from Wakefield, Conn., stilpnomefane pseudomorphs after 
“an unknown tabular mineral,” from Sterling mine, near Antwerp, 
N. Y., and several alteration products of the magnesian limestone 
of Berks county, Pa., are also described and the results of their 
analyses given. 
Microcuemicat REACTIONS.—It is often possible by means of 
a few simple chemical tests to determine the character of a min- 
eral under the microscope without the trouble of separating and 
analyzing it. The methods in most general use for this purpose 
are those of Streng! for the detection of apatite and nepheline, of 
Knop? for the minerals of the Hauyne group, of Boricky® for the 
feldspars and of Behrens‘ for the characteristic elements of many 
other minerals. These and a great many others have been de- 
scribed at length in the various mineralogical magazines, but have 
not, until very lately, been collected and put in shape for ready 
use. Dr. Haushofer, of Munich, has recently brought together 
all those methods which have stood the test of experience, an 
` to these has added others of his own. The result is a compact 
little book® containing minute directions for the detection of fifty’ 
elements by means of simple tests, most of which may be appli 
to the rock section or mineral particle on the stage of the micro- 
scope. The illustrations are good and the directions for working _ 
clearly given. 
I APHIC News.— E. Rethwisch? has made a very 
CRYSTA 
thorough study of pyrargyrite and proustite from an historical, _ 
1A.Streng. Ueber die mikroskopische Unterscheid li d 
tite. Tschermak’s Min. und Pet. Mitth , T ung von nepheline and apa- 
2 A. Knop. Ueber eine mikrochemische reaction auf die Glieder der Hauyn- 44 
familie. Neues Jahrb. der Min., etc., 1875, 
SE. Boricky. Elemente einer neuen chemisch-mikroskopischen Mineral- und Ges- 
teins-analyse. Archiv. ager Landes durchforsch, Béhmehs. r Bd., v Abth, — 
s 564. 
es Jahrb. f. Min., etc., 1879, p 
e 
en Mededeelingen der K. Akad. v. Wetenschappen. Amst fdeeli 
Natuurkunde, 2 Reeks, xvit Deel., pp. 27-7 ppen sterdam, 1881. A 
$ op 
5 roskopische Keactionen, Eine Anleitung zur Erkennung Verschiedener — 
Elemente und Verbindungen unter dem Mikroskop. Vieweg und Sohn, 1885. — 
.162 pp., 137 illus. 
8 Neues Jahrb. für Min., etc. Beilage Band 1v, p. 40. 
zur Mineral-analyse, Verslageñ 
ing f 
Diki 
Bae 
