1893.] Mineralogy and Petrography. 567 
Dakota, but the author’s data were so scanty that Headdon™ has 
thought it advisable to add a small additional contribution -to the 
literature of the mineral. This last-named writer obtained a small 
quantity of what he supposed to be Ulke’s new mineral from both the 
Etta and Peerless mines, and found upon examination that in the 
interior of a small mass from the Peerless mine is a nucleus of stannite 
containing a little cadmium. Intergrown with this and also forming 
an envelope around it is a green clayey substance, which, upon its 
exterior, passes into a yellow earth. The green substance has a density 
of 3.312-3.374. Its analysis shows it to be a mixture of about 7 SnO,, 
6 CuO, 2 FeO and 11 H,O. The author regards it is an alteration 
product of stannite, but not as a well-defined mineral species. 
New Edition of Rosenbusch’s Volume on Minerals.—The 
new edition of Professor Rosenbusch’s Microscopic Physiography of 
the Rock-forming Minerals is an enlargement rather than a revision of 
the second edition. There is no material difference in the arrangement 
of the matter in the two editions, but there have been large additions 
made in the later volume in the shape of descriptions of new petro- 
graphical apparatus and methods, and in the number of minerals 
treated. The plates illustrating the text have been decreased by one. 
The remainder are much better executed than was the case in the 
earlier volume. 
Mineral Syntheses.—Michel” has obtained melanite garnets and 
sphene crystals by cooling slowly a mixture of 10 parts titanic iron, 10 
parts calcium sulphide, 8 parts silica and 2 parts carbon, that had 
been heated to 1200° for five hours. 
Crystallized leucite, potassium eryolite and potassium nepheline results 
from the fusion of silica or of fluosilicate of potassium and alumina 
with an excess of fluoride of potassium. Prolonged heating produces 
leucite, and potassium cryolite. Less prolonged treatment yields 
a potassium nepheline, which crystallizes in negative orthorhombic 
prisms.”, 
Instruments.—For measuring the curves of isotherms on mineral 
plates Jannetaz® has constructed a new ellipsometer, which it is 
l4 : Wee Š 105. ; 
15 ae Sea Oe eee Physiographie der petrographisch wichtigen 
Mineralien, Stuttgart, 1892, pp. 712, Fig. 239, ete. 
18 Bull. Soc. Franc. d. Minn., Vol. xv, p. 237- 
