1882.] COMMERCIAL FERTILIZERS. 69 



to the Connecticut market, but most of it goes to the southern trade. 

 Navassa Island hes southwest of St. Domingo and east of Jamaica. 

 The phosphate deposits were formed under water and thrown up 

 by volcanic action. It contains from 50 to 75^ of phosphate of 

 lime and a considerable amount of oxide of iron and alumina, 

 which makes superphosphates prepared from it "revert" badly. 



I come now to speak of the phosphorite in our own country, 

 the South Carolina phosphate beds, which I believe are, and for 

 some time will be, the chief source of raw material for our domes- 

 tic superphosphate manufacture. 



For most of the facts given in this connection I am indebted to 

 an interesting printed report by Prof. C. U. Shepard, Jr., of 

 Charleston, who has had a more extensive experience in the mat- 

 ter than any one else, and to verbal information received from him. 

 As to the real extent of the deposits which can be worked to 

 advantage, we at present are not fully informed, for the industry is 

 still in its infancy. The existence of vast beds of phosphorite was 

 known before the war, but they were not worked till after its 

 close. This material is found in many places on and near the sea 

 coast, but the larger part hitherto marketed has come from the 

 region lying to the north and northwest of Charleston between the 

 Cooper and Stono Rivers and from the region at the head of St. 

 Helena Sound on the Bull and Coosaw rivers northeast of Beaufort. 

 . It is essentially a phosphate of lime soft enough to be got out 

 witk shovel and pick. The land deposits occur in a stratum from 

 six to fifteen inches thick, though averaging not more than eight 

 inches, and where worked do not lie more than six feet below the 

 surface. 



There are also submarine deposits consisting both of loose 

 material brought down by the current and of fine regular strata. 

 This is known in the market as "river rock." 



The rock is always washed, drained, and dried somewhat before 

 shipment, and some firms dry their material thoroughly by piling 

 it up under cover around tubes which are supplied with hot air. 

 Hot-air dried cargoes at present make up more than half the total 

 amount shipped. 



The extent of the industry is indicated by the following figures : 



There were shipped from Beaufort and Charleston the following 

 amounts of crude phosphate: 



In 1875, ■ - . 122,790 

 1876, - - - 132,626 



