May 17, 1912] 
from assistant in botany to instructor in 
botany. 
Mr. E. N. Zern, professor of coal mining 
at the University of Pittsburgh, has been 
recently appointed professor of mining engi- 
neering at the West Virginia University. 
Mr. George Grow has also been made assistant 
in the College of Engineering at the same 
institution. 
Henry LeicgHTon, formerly instructor in 
the school of mines, University of Pittsburgh, 
has been advanced to be assistant professor of 
economic geology, in charge of the depart- 
ments of economic geology and ceramics. 
Mr. J. W. Cops, B.Se., has been appointed 
to succeed Dr. Bone, F.R.S., as Livesey pro- 
fessor of coal gas and fuel industries at Leeds 
University. 
DISCUSSION AND CORRESPONDENCE 
THE OCCURRENCE OF STIBNITE AT STEAMBOAT 
SPRINGS, NEVADA 
SreamMBoaT Sprines, Nevada, has been often 
cited as an example of a metalliferous deposit 
in the process of formation. Becker’ demon- 
strated the presence of metallic sulphides in 
the waters flowing from the springs and de- 
scribed their occurrence in an amorphous con- 
dition in the spring deposits. He was unable, 
however, to find any of the sulphide minerals 
erystallized. Some years later Lindgren’ an- 
nounced the discovery of minute crystals of 
pyrite and stibnite in sand and gravel that 
had been brought up from the bottom of a 
prospect shaft penetrating the sinter. It was 
evident from the mode of crystallization of 
these minerals that they had been deposited 
from the heated waters of the springs. 
During a recent visit to the springs a gray- 
ish mud was noted in the bottom of several 
pools at the northern end of the sinter terrace, 
about a half mile from the station. On ex- 
amination under a microscope it was seen that 
minute acicular crystals of stibnite made up 
a large proportion of the mud. These were 
1Mon. U. 8. Geol. Survey, Vol. 13, 1888, pp. 
342-344. 
2 Trans. A. I. M. E., Vol. 36, 1906, pp. 27-31. 
SCIENCE 
775 
usually very thin and, when perfect, shaped 
like the blade of a Roman sword with parallel 
edges and blunt point. The crystals were too 
minute for accurate measurement, but the 
forms observed were probably the brachy- and 
macro-pinacoids and a macrodome. ‘The 
larger crystals were frequently split towards 
one end into a narrow fan of finer blades and 
many individual crystals were bent and 
curved. Usually the stibnite was segregated 
in felted balls and occasionally completely sur- 
rounded microscopic grains of sand, which had 
served as nuclei for the forming crystals. 
The remainder of the mud was made up of 
diatom skeletons, fragments of chalcedonic 
quartz, kaolinized feldspar, and occasional 
flakes of mica and hornblende. 
The water in the pools is very clear and 
limpid, with the exception of one unusually 
active spring where the suspended sediment is 
sufficient to make the water turbid. The tem- 
perature of the water in the pools in which 
stibnite was found ranged from 86° C. to 
93° ©., and averaged somewhat higher than 
that of the pools at the southern end of the 
terrace where the antimony sulphide is de- 
posited as an amorphous precipitate. 
Clark® cites the experiments of Doelter 
showing that stibnite is soluble in water 
heated to 80° C., especially in the presence of 
sodium sulphide. Melville’s* analyses of the 
water of Steamboat Springs show sodium 
sulphide to be present. As the temperature of 
the springs in which stibnite was found is 
above that in Doelter’s experiments, it is prob- 
able that the crystallization of the stibnite 
takes place as the heated waters approach the 
surface. 
The complete envelopment of sand grains 
by the stibnite crystals presupposes free sus- 
pension in the water during the period of 
erystallization. The rounded form of the 
balls of felted crystals suggests that they 
formed under similar conditions. It is not 
unlikely that the stibnite crystallizes in the 
2<Data of Geochemistry,’’ U. S. G. S. Bull. 491, 
1911, p. 603. 
“Mon. U. 8. Geol. Survey, Vol. 13, 1888, pp. 347, 
349, 
