VALUE OF FERTILIZERS. 327 



Doctor, " at a price per ton, to be determined by its composition, 

 at the following rates : 



Value per pound. 



Nitrogen (ammonia, 17lc. ) ^lic. 



Soluble phosphoric acid 10 c. 



Reverted u " 8 c. 



Insoluble " " : 2 c. 



Potash, as sulphate and phosphate 7c. 



"The first cargo of Peruvian guano, sold under this guarantee, 

 contained : 



Value per ton. 



Ammonia 6.8 per cent $28.80 



Soluble phosphoric acid.. 3.8 " " 7.60 



Reverted " " ..11.5 " " 18.40 



Insoluble " .. 3.0 " " 1.20 



Potash 3.7 " " 5.55 



Estimated retail price per ton of 2,000 Ibs $56.;;5 



Marked on bags for sale $50.00 



The second cargo, sold under this guarantee, contained : 



Value per ton, 



Ammonia 11.5 per cent $40.50 



Soluble phosphoric acid.. 5.4 " " J0.80 



Reverted " " ..10.0 " " 16.00 



Insoluble " " .. 1.7 " " 68 



Potash 2.3 " " 3.45 



$71.43 

 Selling price marked on bags .-$70.00 



** It is interesting," said I, "to compare these analyses of Peru- 

 vian guano of to-day, with Peruvian guano brought to England 

 twenty-nine or thirty years ago. I saw at Rothamsted thirty years 

 ago a bag of guano that contained 22 per cent of ammonia. And 

 farmers could then buy guano guaranteed by the dealers (not by 

 the agents of the Peruvian Government), to contain 1G per cent of 

 ammonia, and 10 per cent of phosphoric acid. Price, 9 5s. per 

 ton of 2,240 Ibs. say $40 per ton of 2,000 Ibs. 



The average composition of thirty-two cargoes of guano im- 

 ported into England in 1849 was as follows: 



Ammonia 17.41 per cent. 



Phosphoric acid 9.75 " " 



Alkaline salts 8.75 " 



At the present valuation, adopted by the Agents of the Peruvian 

 guano in New York, and estimating that 5 per cent of the phos- 

 phoric acid was soluble, and 4 per cent reverted, and that there 

 was 2 Ibs. of potash in the alkaline salts, this guano would be 

 worth : 



