﻿2 BULLETIN 18, U. S. DEPARTMENT OE AGRICULTURE. 



no determination other tlmn that of their lime content was made. 

 Holmes, 1 in 1844, described " a remarkable bed of nodules or conglom- 

 erates 12 inches thick bedded in clay which overlaid the heavy beds 

 of marl." 



Tuomey, 2 who succeeded Ruffin, issued a report in 1848 in which 

 he described the same stratum and called the phosphate nodules 

 "marl stones." He was convinced that they were derived from the 

 underlying marl, for lie says, "There is little more left than the silica 

 and alumina of the marl." In the appendix of this same report 3 are 

 a number of analyses made by Prof. Charles U. Shepard showing the 

 phosphate content of the marl, but none showing the amount of phos- 

 phoric acid in the nodules. Holmes,' in a later publication, also 

 regards the phosphate nodules as sihcified fragments of the underlying 

 marl. 



Chazal 5 states that Prof. Charles U. Shepard was the first to point 

 out the true value of the phosphate nodules. He quotes from a lec- 

 ture delivered by Shepard before the medical society in 1859, which 

 indicates that the latter was then acquainted with the nature of the 

 phosphate stratum. Chazal also quotes from letters which show that 

 Shepard had advised the use of the Ashley phosphates in lieu of bones 

 as far back as 1860. The outbreak of the Civil War, however, put a 

 stop to fertilizer operations, and it was not until 1867 that Dr. St. 

 Julien Ravanel, Dr. F. S. Holmes, and Dr. N. A. Pratt revived inter- 

 est m these deposits and obtained capital sufficient for their exploita- 

 tion. To Dr. Pratt belongs the credit of the first recorded analysis 

 of high-grade South Carolina phosphate. 



From 1868, when 12,262 tons of rock were produced from the South 

 Carolina fields, to the year 1893, which showed a production of 

 618,569 tons, the industry steadily grew, but since the latter date the 

 production has diminished, till in 1911 the total amount mined was 

 only 169,156 tons. 



GEOGRAPHY AND TOPOGRAPHY. 



The phosphate area of South Carolina lies along the coast in a belt, 

 which is hi places fully 20 miles wide, extending from the Wando River 

 hi Charleston County to the Broad River hi Beaufort County. (See 

 fig. 1.) The coast region as a whole is very little above tide level 

 and is intersected with numerous creeks, rivers, and arms of the sea. 

 Most of these streams are navigable and afford the phosphate oper- 

 ators a ready means of transportation for their product. Many of 



1 South Carolina Agriculturist (1844). 



2 Geology of South Carolina, p. 165 (1848). 



a Geology of South Carolina. Appendix (1848). 



' Post Pliocene Fossils of South Carolina. Introduction, p. n (!8(i0). 



s A Sketch of the South Carolina Phosphate Industry (1904). 



