PRINCIPAL PHOSPHATE DEPOSITS. 



35 



about 160 square miles, between Barlow, Fort Meade, Chicora, 

 and Callsville. The land of this district is flat like all South 

 Florida, with low undulations here and there. Under the surface 

 bed of sand, phosphatic clay is found almost everywhere. As 

 already mentioned, land pebbles can hardly be distinguished from 

 river pebbles. They are paler and purer than the latter; their 

 phosphate of lime content reaches 72 to 75 per cent, on an average 

 66 to 68 per cent, with 2-3 per cent of oxide of iron and alumina. 

 An average sample gave the following results : — 



TABLE XXV.— ANALYSIS OF LAND PEBBLE PHOSPHATE. 



Per cent. 

 Phosphoric acid 33-61 



Loss on ignition 



Lime . 

 Oxide of iron 

 Oxide of alumina 



Magnesia 

 Carbonic acid 

 Silica . 



0-79 

 48-08 

 1-20 

 1-38 

 5-54 

 2-29 

 7-15 



Tennessee. — As far back as 1892, the presence of a very ex- 

 tensive phosphate level in the south of the central region of Ten- 

 nessee, chiefly in Mount Pleasant County, in the districts of Maury 

 and Perry, was discovered. The bed is found below the Devonian 

 schists of Chattanooga. The phosphate occurs under two different 

 forms; in the upper part, that is to say, immediately below the 

 greyish-blue shales of Harpeth, phosphatic nodules are found, 

 then comes a bed of black schists termed Chattanooga, and finally 

 a uniform bed of about 1 metre in thickness of rock phosphate 

 resting directly on limestone which ends the formation. Samples 

 of this rock phosphate from the best-known parts gave the follow- 

 ing average results (D. Levatt) : — 



TABLE XXVL— ANALYSIS OF TENNESSEE ROCK PHOSPHATE. 



Phosphoric acid 



Oxide of iron 



Insoluble matter 



Lime 



Sulphur 



Carbonic acid, COg 



Moisture 



Per cent. 



26-74 to 31-94 

 2-32 „ 6-92 

 2-70 „ 7-06 



29-60 „ 41-30 

 0-00 „ 4-00 

 0-00 ., 1-50 

 0-20 „ 0-60 



Bemarks on the Actual Condition of the Phosphate Industry in 

 America. — In the Southern States of the Union, there is a manifest 

 tendency to concentrate businesses into the same hands. Thus for 

 the hard rocks of Florida, there were 70 declarations of exploita- 

 tion in 1902, 60 in 1903, 18 in 1904, 14 in 1905, and 16 in 

 1906. On the exploitations declared in 1906, 10 were at work. 



