VAI.UK OF FERTILIZERS. 327 



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

 at the following rates: 



Valiu2Kr pouTid. 



Nltrocen (ammonia, ITlc. ) 2Uc. 



Soluble pbos|>horic acid 10 c. 



Reverted " " 8 c. 



Insoluble " " 3 c. 



Potash, as sulphate and phosphate Tic. 



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

 contained : 



Value j)er ton. 



Ammonia fi.S per cent 123.80 



Soluble phosphoric acid.. 3.8 " " 7.60 



Reverted " " ..11.5 " " 18. -W 



Insoluble " " .. 3.0 " " 1.20 



Potash 3.7 " " .^ 5^ 



Estimated retail price per ton of 2,0(K) lbs $56..'i5 



Marked on bags for sale :$5G.00 



The second cargo, sold under this guarantee, contained : 



Value jjer ton. 



Ammonia 11.5 per cent $40.50 



Soluble phosphoric acid. . 5.4 " " 10.80 



Reverted " " ..10.0 " " 16.00 



Insoluble " " .. 1.7 " " 68 



Potash 2.3 " " •^A'*? 



$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 16 per cent of 

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

 ton of 2,240 lbs.— say $40 per ton of 2,000 lbs. 



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 i)er cent reverted, and that there 

 was 2 lbs. of potash in the allialine salts, this guano would be 

 worth : 



