Review of Recent Geological Literature. 269 
suggests that the "mineral pyroxene of the white or colorless variety, 
occuring often in the lower layers and filling some of the canals" of 
the Eozoon, as described by Dr. Dawson, is but the residual mineral 
that has escaped alteration. 
A deadly gas-spring in the Yelloivstone National Park. Mr. Walter H. 
Weed describes in Science, Feb. 15, 1889, a remarkable place to which 
the appropriate name of Death gulch is given. It was discovered by Mr. 
Weed in the summer of 1888, while making geological examination of 
the region. It is in the extreme N. E. portion of the reservation. It is on 
Cache creek, two miles above its confluence with Lamar river. A ra- 
vine here is so charged with gaseous emanations that bears, elk, squir- 
rels and other animals, as well as butterflies and insects are asphyxiat- 
ed before they can escape. It is a V-shaped trench, not over seventy- 
five feet deep, cut in a mountain slope, and not a hollow, or cave. The 
gas which constantly escapes results from the prevalence of volcanic 
agents in the region. "Death gulch is without a peer as a natural 
bear-trap, and may well be added to the list of wonders of the Yel- 
lowstone Park." 
Geological Survey of Arkansas : Second Annual Report of the State Ge- 
ologist; in 4 volumes. Vol I. Dr. Branner is conducting a work in the 
state of Arkansas for which American men of science should feel grate- 
ful, and the first volume of his report shows that he has done his work 
in a fearless, honest straight-forward manner, under the impression 
that the object of a state geological survey, is to make a geological sur- 
vey of the state, and not to provide political dependents with ofiice or 
to boom speculative enterprises. As a result of rigid adherence to this 
line of policy after two years of labor upon the small appropriation of 
$10,000 a year, in a region most difficult to investigate and against hy- 
gienic and prejudical obstacles not ordinarily encountered, he presents 
for publication four volumes of results which throw the first intelligible 
light we have yet had upon that region. Since Dr. Branner's constit- 
uency was impregnated with the idea that geology is merely the study 
of metallic minerals, and since the state was flooded with fraudulent 
mineralogists and assayists who were finding gold and riches in mar- 
velous plenitude, the first step of the geologist was to have the mineral 
resources thoroughly investigated, the resuTC of which is embraced in 
Vol. 1, which lies before us. 
This report, written by Prof. Theo. B. Comstock, although mostly 
negative in its opinions of value, sets forth thoroughly and exhaustive- 
ly the exact geologic and economic conditions of the region studied, 
and will save prospectors far more than its cost, and relieve true geo- 
logic investigation of the future of the "mineral" incubus. From a 
scientific standpoint, while presenting some defects, it is an excellent 
contribution, and contains much new and interesting geologic data, 
especially concerning the heretofore little known mountain region of 
southwest Arkansas. The chemical and petrographic work, by Dr. R. 
N. Brackett is also up to the standard of to-day. 
