NAVASSA ISLAND PHOSPHATES. 373 



Navassa Phosphate. 



This mineral phosphate, which has been imported since 

 1856, occurs in large quantities upon Navassa, a small coral 

 island, about thirty-three miles to the south-west of Hayti, 

 and seventy-two miles to the east of Jamaica.* The Navassa 

 phosphate furnishes, in common with the South Carolina 

 phosphate, at present, to a large degree, the crude stock for 

 the manufacture of superphosphates for the Southern trade. 

 As it is used to some extent, and in part for similar purposes, 

 in a large factory within the vicinity of Boston, I secured 

 samples from the office of the Navassa Phosphate Company, 

 at Baltimore, Md., with the intention to study, by personal 

 observation, their properties. 



One portion of them consisted of pieces from three to four 

 inches long, and several inches wide ; the rest formed a 

 granular mass, the grains being of various sizes and of a dif- 

 ferent degree of hardness. Both kinds varied in color from 

 white to red brown ; evidently due to a varying percentage of 

 sesquioxide of iron in a combined and an uncombined state. 



The material which in the larger pieces serves as a cement 

 of the conglomerate, is apparently richer in phosphoric acid 

 than the main bulk of the grauular mass. Numerous analyses 

 state the average percentage of phosphoric acid in the Na- 

 vassa phosphate to be from 32 to 34 per cent. The sample 

 which I tested gave the following : — 



Loss by calcination, . . . . .9.60 parts. 



Insoluble in hydrochloric acid, . . . 2.70 " 



Insoluble phosphoric acid, .... 34.09 " 



Calcium oxide, 37.67 " 



Sesquioxide of iron, ..... 8.75 " 



Alumina, ....... 4.24 " 



The Navassa Phosphate Company offers 2,240 pounds for 

 $14, in cases of entire cargoes, direct from the island; the 

 same amount, in a finely-ground state, sells at $17.50 in Bal- 

 timore, and at $18 in New York. Their phosphate is one of 

 the richest mineral phosphates at present in our markets. Its 



* Memoir on the Island of Navassa, by Eugene Gaussoin. Baltimore, Md., 1866. 



