28 BULLETIN 798, U. S. DEPARTMENT OF AGRICULTURE. 
MANURE. 
Beal, W. H. Barnyard manure. Farmers’ Bul. 192. 32p. 1904. 
Brodie, D. A. Handling barnyard manure in eastern Pennsylvania. Farmers’ Bul. 
978. 24p. 4fig. 1918 
White, H.C. Barnyard manure. Farmers’ Bul. 192. 16 p. 1897. 
PEAT. 
Turp, James S. Peatin 1915. U.S. Geol. Surv., Mineral resources of the United 
States, 1915, pt. 2:34. 4p. 
PHOSPHORUS. 
Stone, Ralph W. Phosphate rock in 1917 with notes on phosphorus. U. S. Geol. 
Surv., Mineral resources of the United States, 1917, pt. 2:3, p. 7-18. 
Stone, R. W. Our mineral supplies—phosphate rock. U. S. Geol. Surv. Bul. 
666-J. [1917] 4p. 
Waggaman, W. H., and Wagner, C. R. Analysis of experimental work with ground 
raw rock phosphate as a fertilizer. Dept. Bul. 699. 119 p. 1918. 
Waggaman, William H. The manufacture of acid phosphate. Dept. Bul. 144. 28 p., 
5 pl. 1914. 
Waggaman, William H., and Fry, William H. Phosphate rock and methods proposed 
for its utilization as a fertilizer. Dept. Bul. 312. 37 p. 1915. 
Waggaman, William H. Phosphate rock our greatest fertilizer asset. Yearbook 
1917, p. 177-183. Sep. 730. 
Waggaman, William H. The production and fertilizer value of citric-soluble phos- 
phoric acid and potash. Dept. Bul. 143. 12p. 1914. 
Waggaman, William H. A report of the natural phosphates of Tennessee, Kentucky, 
and Arkansas. Soils Bul. 81. 36p. 4pl. 1912. 
Waggaman, William H. Report on phosphate fields of South Carolina. Dept. Bul. 
18. 2 peopl. sho AST. 
Waggaman,W.H. Review of phosphate fields of Florida. Soils Bul.76. 23p. 1911. 
Waggaman, W. H. A review of phosphate fields of Idaho, Utah and Wyoming. 
Soils Bul. 69. 48 p. 1910. 
Waggaman, William H. The utilization of acid and basic slags in the manufacture 
of fertilizer. Soils Bul. 95. 18 p. 1913. 
POTASH. 
Brown, Frederick W. Importance of developing our natural resources of potash. 
Yearbook 1916, p. 301-310. 3 fig. Sep. 717. 
Cameron, Frank K. Possible sources of potash in United States. Yearbook 1912, 
p. 523-536. Sep. 611. 
Cameron, Frank K. Potash from kelp. U.S. Dept. Agr. Rpt. 100. 122 p., xl pl. 
1915. Atlasof69 maps 1914. 
Cushman, Allerton S. The use of feldspathic rocks as fertilizers. Plant Industry 
Bul. 104. 32 p. 1907. 
Free, E.E. Aninvestigation of the Otero Basin, New Mexico, for potash salts. Soils 
Cire. 61. 7p. 1912. 
Gale, Hoyt S. Our mineral supplies—potash. U.S. Geol. Surv. Bul. 666-N [1917] 
4p. 
Mid-year statistics on production of potash. U.S. Geol. Surv., Press Bul. 379, p. 4. 
Sept. 1918. 
Phalen, W. C. Potash salts 1915 with bibliography by W. C. Phalen, with simple 
tests for potash by W. B. Hicks. U. S. Geol. Surv., Mineral resources of the 
United States, 1915, pt. 2, p. 95-133. 
atitenen ta amend 
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