PIlOSPHATl'S 73 



Average Composition of Organic Phosphates of Lime. 



Raw bone-meal 



Steamed bone-meal • 



Bone-black 



Bone-ash 



Bone tankage 



Dry ground fish 



Phosphoric acid 

 Per cent. 



Nitrogen 

 Per cent. 



22 I 3-5 



25 2.5 



30 



36 — 



r.5-20 I 4-6 



9 I 8.5 



The phosphoric acid present in raw bone-meal, steamed bone- 

 meal, bone tankage, bone-black, bone-ash and dry ground fish 

 is insoluble in water and slowly available as plant food. 



Mineral Phosphates. — These occur in natural beds in different 

 parts of the world. According to Van Horn in the American 

 Fertilizer, the known phosphate deposits of the United States are 

 distributed principally among four localities: (i) along the 

 west coast of Florida, running back 20 to 25 miles inland; (2) 

 along the coast of South Carolina, extending 6 to 20 miles in- 

 land ; (3) in central Tennessee; and (4) in an area comprising 

 southeastern Idaho, southwestern Wyoming, and northeastern 

 Utah. In addition to these areas, some deposits occur in north- 

 central Arkansas, along the Georgia-Florida State line, and in 

 North Carolina, Alabama, Mississippi, and Nevada, but these are 

 mainly of low grade and not utilized at the present time. The 

 three important deposits first mentioned have been worked from 

 ten to thirty years ; the fourth is a new field which has as yet had 

 but a small output.''' 



The most important deposits in this country are in Florida, 

 South Carolina, and Tennessee and the production in the 

 United States amounts to over two million long tons (2,240 

 pounds) a year while that of the remaining countries approxi- 

 mates one million tons. 



South Carolina phosphates were first put upon the market in 

 1868. There are two kinds of phosphates found in South Caro- 

 lina, namely, the land and river phosphates. The land phosphate 

 IS mined from the land and is known as land rock, while the 

 river phosphate is obtained by dredging rivers and is called river 



