1895.] Mineralogy. 149 
crystals by bringing upon an object glass a large drop of a saturated 
solution of sodium or potassium chloride or a mixture of the two salts, 
and placing to one side of this a drop of calcium chloride solution, and 
on the other side a drop of Epsom salt solution. The three drops are 
joined to one another by narrow paths and evaporated. During the 
diffusion of the liquids which takes place, calcium sulphate is formed 
and appears in crystals of both gypsum and anhydrite along with the 
crystals of the chlorides. When a little water is added to a group of 
anhydrite crystals they are dissolved to recrystallize as gypsum. By 
properly regulating the amount of water added, Knatiel of gypsum 
may be formed with a corroded core of anhydrite. Although anhy- 
drite has been frequently produced artificially, none of the methods 
heretofore used have simulated its production in nature from the evap- 
oration of sea water. 
Artificial Crystals of Zinc Oxide.—Ries* has examined artifi- 
cial crystals of zinc oxide from the New Jersey Zine Works and found 
them to possess the combinations (110), (225); (110), (112); and 
(110), (124): the form (124) being new. The crystals examined were 
colorless, transparent, holohedral, and devoid of basal cleavage. 
Artificial Copper Crystals in Aventurine Glass.— W ashing- 
ton’ has made a microscopical study of the aventurine glass from the 
famous Murano near Venice. The spangles of copper appear in large 
and small phenocrysts and in microlites. The large phenocrysts are 
.05-.12 mm. in diameter, of tabular habit, and not over .002 mm. thick 
They are generally hexagonal in outline, but some are equilateral tri- 
angles with the angles somewhat truncated. Distinct skeleton forms 
appear among the commoner individuals with plane faces. These 
erystals are all doubtless octahedra flattened parallel to an octahedral 
face, a habit which Dana has shown to be common in the case of cop- 
per crystals. Some individuals exhibited the distorted combination of 
cube and octahedron, while others were cyclic twins parallel to an 
octahedral face and either vierlings or fiinflings, the latter poneo 
a closed form. 
New Minerals, Neptunite and Epididymite.—Flink® describes in 
detail two new minerals associated with egerine from Greenland. The 
exact locality is not certainly known, but it is thought to be near 
*Am. Jour. Sci., xlviii, p. 256, Sept., 1894. 
5 Am. Jour. Sci., xlviii, pp. 411-418, N 1894. 
ê Zeitsch. f. Kryst., xxiii, pp. 344-367, 1894. 
