38 report — 1865. 



more valuable ; for in the deeper specimens the proportion of phosphate of lime 



amounted to 64| per cent. 



This phosphatic mine is readily accessible and naturally drainable to a depth of 



about 500 feet, and contains many hundred thousand, if not millions of tons of 



valuable phosphatic minerals. 

 The following analyses may be given in illustration of the composition of the 



limestone and the black shale deposits. 



A specimen of phosphatic limestone gave the following results : — 



Phosphoric acid 16T2 



Lime 3042 



Oxide of iron 2-34 



Alumina 6-52 



Magnesia 4-89 



Iron 1-30 ) 



Sulphur 1-49 \ 



Carbonic acid 12-23 



Insoluble siliceous matter 20-95 



Sulphuric acid - 16 



Organic matter and loss 3 - 58 



These constituents, united together in the usual manner, give the following com- 

 position for this phosphatic limestone : — 



Tribasic phosphate of lime 34 - 92 



Oxide of iron 2-34 



Alumina 6 - 52 



Carbonate of lime 20 - 75 



Carbonate of magnesia 5-92 



Magnesia in a state of silicate 2-07 



Iron pyrites '. 2 - 79 



Sulphuric acid '16 



Insoluble siliceous matter '. 20-95 



Organic matter and loss 3 - 58 



100-00 

 A specimen of black phosphatic shale, found at a depth of about 20 feet below 

 the surface, furnished the following results : — 



Organic matter and loss 3-98~ 



Lime 37-16 



Phosphoric acid* 29-67 



Magnesia -14 



Oxide of iron 1-07 



Alumina 5-84^ 



Matters insoluble iu dilute hydrochloric acid 22-14 



Soluble in dilute 



hydrochloric 



acid. 



10000 

 A specimen of black phosphatic shale, taken at a depth of about 12 feet, on 

 analysis yielded the following results : — 



Phosphoric acid 24-07 



Lime 3231 



Oxide of iron 2-01 



Alumina 7-71 



Magnesia -32 



Sulphuric acid -26 



Iron 3-51 1 



Sulphur 4-01 j 



Insoluble siliceous matter 22-44 



Organic matter and loss 3-36 



10000 

 * Equal to tribasic phosphate of lime , 64'16 



