Review of Recent Geological Literature. 331 
Sections crossing the Piedmont plateau show throughout very steep 
or vertical or overturned dips ; and it is believed that they comprise 
many sharp folds and faults. The most probable hypothesis of the 
structure of this area in Maryland, according to Prof. Williams, sup- 
poses that the eastern rocks are far more ancient than the western and 
extend beneath the latter, forming the floor on which they were de- 
posited ; and that this crystalline floor, previously much folded and 
metamorphosed, underwent at least one more folding after the western 
schists had been laid down, the latter then acquiring their cleavage and 
partial metamorhism. 
The section studied and described by Mr. Keyes extends from Catoc- 
tin mountain southeastward across Sugarloaf mountain and onward to 
Washington. It includes the fossiliferous Frederick limestone, which 
is referred to the Trenton period. 
Electro-Chemical Analysis. By Edgar F. Smith, 12mo., 116 pp. 
Philadelphia, P. Blakiston, Son & Co., 1890. 
This little volume will be useful to those students and others who 
wish to become acquainted with the methods of quantitive analysis by 
electrolysis, which are generally omitted from the larger text books. 
It contains also a historical review of the introduction of the electric 
current into chemical analysis. 
Geological Survey of Kentucky. Report on the geology of Whiteley 
county and part of Pulaski. With plates and other illustrations, 44 pp. 
Roy. oct., and a geological map. By A. R. Ckandall. This is one of 
those admirable county reports for which the Kentucky survey is well 
known. The geology of the county embraces a range from the Coal 
Measures to the Devonian ; and covers a belt which is well known for 
its bold topographic features and contrasts, from Ohio to Tennessee. In 
the southeastern part of the county the geology and topography are 
varied by the Pine mountain fault, which runs northeastwardly and 
which causes the exposure of the lower members of the Devonian in the 
midst of an area of the Coal Measures. The report gives the details of 
the stratigraphy involving the separate beds of coal, and is finely illus- 
trated by several plates of reproduced photographs of important topo- 
graphic and scenic landscapes. 
There is, however, one defect which we note in this report, one which 
we have noticed in several of the Kentucky reports — it has no date. 
From cover to cover there is no evidence to show what year in the ad- 
ministration of Prof. Proctor the report was published. 
Geological Survey of Kentucky. Report on the geology of Clinton. 
county, with a map. By R. H. Lotjghrtdge, pp. 48, Roy. octavo. Sub- 
mitted Feb., 1890. This county ranges from the lower Coal Measures to 
the Cambrian (Hudson River), descending from the southeast toward 
the northwest. Poplar mountain, and some hills further west, consti- 
tute the extreme western limit of the Cumberland mountains within 
Kentucky. The author gives various local.sections and some chemical 
analyses of coals. Oil and gas have been known in the county for sev- 
