BIBLIOGRAPHY OR FLORIDA PHOSPHATES. 
73 
1891. Shrader, Jay: 
Hidden Treasures, Bartow, 1891.* Extract included in 
The Phosphate Industry of Florida by Carroll D. 
Wright, Sixth Special Report of the Commissioner of 
Labor, p. 39, 1893. 
An account is included in this pamphlet of the discovery 
by J. Francis LeBaron of pebble phosphate on Peace 
Creek in 1881. 
1891. Cox, E. T.: 
Floridite: A New Variety of Phosphate of Lime. Am. 
Assoc. Adv. Sci. Proc., XXXIX, pp. 260-262, 1891. 
Read before the Indianapolis meeting, Amer. Assoc, for 
the Advancement of Sci., August, 1890. 
In this paper Cox advances the theory that the hard 
rock phosphate represents ancient guano which has become 
mineralized. 
1891. Dali, W. H.: 
On the Age of the Peace Creek Beds, Florida. Acad. Nat. 
Sci., Phila., Proc. 120, (1-3 p.), 1891; abst. Am. Geol. 
VII, 382, 1891.* 
1891. Darton, N. H.: 
Notes on the Geology of the Florida Phosphate Deposits. 
Am. Jour. Sci. (3) XLI, pp. 102-105, February, 1891; 
abst. Eng. Min. Jour. LI, p. 210 (1cols.), 1891. 
Guano is regarded by Darton as a probable source of 
the rock phosphate. The phosphate of Polk County is 
referred to as a conglomerate and is believed to have been 
derived from the hard rock phosphates. 
1891. Davidson, Walter B. M.: 
Suggestions as to the Origin and Deposition of Florida 
Phosphate. Eng. Min. Jour. LI, pp. 628-629, 1891.* 
Regards the hard rock phosphate boulders as having 
been deposited in underground caverns and river beds in 
the Vicksburg Limestone. 
