G. F. Becker—Solutions of Cinnabar, Gold, ete. 199 
The results of the optical examination are fully in accord 
with a series of chemical tests which Dr. C. Pigot, assistant in 
the Chemical Laboratory of the Johns Hopkins University, 
kindly made forme. The powder of the mineral, which had 
been separated from the fibrolite by the boro-tungstate of 
cadmium solution and from the magnetite by boiling it in hy- 
drochloric acid, was found not. to be attacked by any acids. 
It is very difficultly fusible with sodium carbonate but fuses 
readily with acid potassium sulphate or acid sodium sulphate. 
In the solution thus obtained the presence of nothing except 
alumina and iron could be detected. The only unusual prop- 
erty of this corundum is a lower specific gravity than was ex- 
pected. This is probably due to incipient alteration, which 
can be easily seen under the microscope, and is another cause 
that would tend to materially diminish the value of the West- 
chester Co. emery. 
In a succeeding paper the writer hopes to describe the remain- 
ing members of the Cortlandt Series (gabbros and diorites) and 
to point out the metamorphosing effect which the massive rocks 
have exercised upon the surrounding schists and limestones, 
as well as other proofs of their undoubted eruptive character. 
Petrographical Laboratory of the Johns Hopkins University, 
Baltimore, December, 1886. 
Art. XXIII.—WNatural solutions of Cinnabar, Gold and asso- 
. ciated sulphides ; by GEORGE F. BECKER. 
In the course of investigations on the geology of the quicksil- 
ver deposits of the Pacific slope [ have taken up the question of 
the state of combination in which quicksilver is dissolved in 
natural waters. Pyrite or marcasite almost invariably accom- 
panies cinnabar, gold is known to be associated with cinnabar 
in a considerable number of cases, copper sulphides or sulpho- 
salts are also not infrequent in quicksilver mines, and sulphides 
of arsenic and antimony are known to occur in a similar associa- 
tion. Zincblende too has been found with cinnabar. The solu- 
bility of these substances has been incidentally examined. In 
performing the experiments I had the assistance of Dr. W. H. 
Melville, who also made all the quantitative analyses involved. 
The results obtained seem interesting enough tojustify their pub- 
lication, in an abbreviated form, in advance of the monograph 
of which they will form a part. They also possess some value 
from a purely chemical point of view, and may interest readers 
of this Journal who are not geologists. . 
Am. Jour. Sci—Tuirp Series, Vou. XXXIII, No. 195.—Marou, 1887. 
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