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thickness, is composed entirely of the massive and semi-crys- 

 talline phosphate, and it follows the lower portion with a pretty 

 uniform dip and parallelism to the depth of about thirty feet, as 

 far as it has been explored. It extends to the surface of the 

 ground, and was opened for the purpose of obtaining pyrites for 

 the manufacture of copperas, or green vitriol, which it was 

 thought would pay the cost of mining, while the phosphate of 

 lime was overlooked, or supposed to be some common rock, 

 though the occurrence of a few crystals of the mineral imbed- 

 ded in the pyrites had been known for some time, and had 

 attracted various mineralogists to the spot. There may be seen 

 a single crystal at the residence of Governor Dickinson, which 

 must have been more than eicjhteen inches in length. The 

 massive phosphorite was discovered by Dr. C. T. Jackson and 

 Mr. Alger while on an excursion into New Jersey during the 

 past summer. Several tons of it have been removed, and its 

 value is soon to be tested as a substitute for animal phosphate 

 and guano, as an agricultural fertilizer, after being ground, and 

 undergoing other suitable preparations to render it most readily 

 solvent and active in the soil. So important is this substance 

 deemed, that a few years since the British Government sent 

 commissioners to Estremadura, in Spain, for the purpose of 

 exporting it to England, and Prof. Daubeny made a report on 

 the subject, the result of which was, that it did not occur in 

 sufficient quantity, so that the only mineral phosphate now used 

 by the agriculturalists in England is obtained from the crag on 

 the coast of Suffolk. But this is very impure, containing car- 

 bonate of lime and other earthy matter, which Prof. Johnstone 

 says are objectionable in several ways, while the massive phos- 

 phate of New Jersey is perfectly pure. Prepared bone dust, 

 however, is very largely used in England, and in this country 

 the demand for it is considerable. This prepared bone contains 

 several soluble phosphates besides lime, as magnesia and soda, 

 all of which are important to the growth of plants. When we 

 consider the bearing of phosphate of lime upon the animal and 

 vegetable economy, and that our own bones and teeth are so 

 largely composed of it and derive it, as they only can, from the 

 vegetable kingdom, we see how important it is that the soil 

 which is to afford us our food should be supplied with it as it is 



