BIBLIOGRAPHY OF NORTH AMERICAN GEOLOGY, 190G-1907. 41 
Campbell, Marius R. — Continued. 
399. Survey work on coal during 1905.— T T . S. Geol. Survey, Bull. no. 285, 
pp. 203-210, 1906. 
A summary account of the work of the U. S. Geological Survey in examining coal 
deposits and testing the fuel value of the coals. 
400. Character and use of the Yampa coals. — TJ. S. Geol. Survey, Bull. no. 
297, pp. 82-91, 1906. 
Descrihes the chemical composition, classification, and utilization. Discusses briefly 
the classification of coals. 
401. Plow long will the coal reserves of the United States last? — Nat. Geog. 
Mag., vol. 18, no. 2, pp. 129-138, 1 fig., February, 1907. 
Contains notes on the distribution and extent of the coal fields and the character of 
the coals. 
402. Contributions to economic geology, 1906, part II. Coal, lignite, and 
peat: Introduction.— U. S. Geol. Survey, Bull. no. 316, pp. 5-12, 1907. 
CJives an outline of the work of the TT. S. Geological Survey in 1006 upon coal, lignite, 
and peat. 
403. The Una del Gato coal field, Sandoval County, X. Mew— U. S. Geol. 
Survey, Bull. no. 316, pp. 427^30, 1 fig., 1907. 
404. Coal in the vicinity of- Fort Stanton Reservation, Lincoln County, 
N. Mex.— U. S. Geol. Survey, Bull. no. 316, pp. 431^34, 1 fig., 1907. 
405. Coal of Stone Canyon, Monterey County, Cal.— IT. S. Geol. Survey, Bull, 
no. 316, pp. 435^38, 1907. 
Report on the operations of the coal-testing plant of the United States Geo- 
logical Survey at the Louisiana Purchase Exposition, St. Louis, Mo., 1904. — See 
Parker, Holmes, Campbell, no. 1870. * 
Mineral resources of the United States in 1905 : peat. — See no. 2418. 
Contributions to economic geology, 1906. Part II, Coal, lignite, and peat. — 
See U. S. Geological Survey. 
Campbell, William. 
406. The microscopic examination of opaque minerals. — Econ. Geology, vol. 
1, no. 8, pp. 751-766, 7 figs., 1906. 
407. Notes on the microscopic examination of the opaque constituents of ore 
bodies.. — Abstract: Science, new ser., vol. 24, p. 691, November 30, 1906. 
Campbell, William, and Knight, C. W. 
408. The paragenesis of the cobalt-nickel arsenides and silver deposits 
of Timiskaming [Ontario ].— Eng. and Min. Jour., vol. si, pp. 1089-1091, 13 figs., 
June 9, 1906. 
An investigation of the order in which the minerals occurring in the ores have been 
deposited and the relations which the gangue (calcite) bears to them. 
409. Microscopic examination of nickeliferous pyrrhotites. Results of a 
study to settle a much-diseussed question in ore deposit ion. — Eng. ami .Min. 
Jour., vol. 82, pp. 909-912, 6 figs., November 17, 1906. 
410. A microscopic examination of the cobalt nickel arsenides and silver 
deposits of Temiskaming. — Econ. Geology, vol. 1, no. 8, pp. 707-77C,. l ( pis.. 1906. 
Describes the structure shown by microscopic examination and the order of origin <>f 
the principal constituents. 
411. On the microstructure of nickeliferous pyrrhotites. Econ. Geology, 
vol. 2, no. 4, pp. 350-366, 4 pis., June, 1907. 
Camsell, Charles. 
412. f Report on the] Peel River, in the Yukon and Mackenzie districts.— 
Canada, Geol. Survey, Summ. Rept. for 1905. pp. :!<; )<;. L906. 
Describes the exploration of the region. Includes various data npoii i^ geology. 
