HISTORY OF THE AMERICAN MENHADEN. 237 



Tbe following rates of valuation were adopted by Professor Goess- 

 mann in 1874-'75 and 1875-'76 : 



l&74-'75. 187ri-'76. 



, Per pound. Per pound. 



Soluble phosphoric acid 16.25 cents. 12.5 cents. 



Reduced , 13 cents. 10 cents. 



Insi In ble phosphoric acid in mineral phosphates 5 cents. 4 cents. 



Insoluble phosphoric acid in bones, fish, and animal dust 6 cents. 6 cents. 



Nitrogen 30 cents. 25 cenis. 



Potassium oxide in mnriate 8 cents. 6 cents. 



Potassium oxide in sulphate 8 cents. 8 cents. 



Professor Johnson, in tbe report of the Connecticut station for 1877, 

 says as follows : 



''Tbe following are the trade-values or cost in market, per pound, of 

 the ordinarily occurring forms of nitrogen, phospboric acid, and potash, 

 as recently found in the New York and I^ew England markets : 



Cents par pound. 



Nitrogen in ammonia and nitrates 24 



Nitrogen in Peruvian guano, fine steamed bone, dried and fine-ground bljod, 



meat, and fish 20 



Nitrogen in fine-ground bone, horn, and wool dust 18 



Nitrogen in coarse bone, horn shavings, and fish scrap 15 



Phosphoric acid soluble in water 12i 



Phosphoric acid ' reverted' and in Peruvian guano 9 



Phosphoric acid, insoluble, in fine bone and fish guano 7 



Phosphoric acid, insoluble, in coarse bone, bone ash, and bone-black 5 



Phosphoric acid, insoluble, in fine ground rock phosphate 3|^ 



Potash in high-grade sulphate 9 



Potash in kainit as sulphate "71 



Potash in muriate or potassium chloride 9 



" Tbese ' estimated values' are not fixed, but vary with tbe state of 

 the market, and are from time to time subject to revision. They are not 

 exact to the cent or its fractions, because the same article sells cheaper 

 at commercial or manufacturing centers than in country towns, cheaper 

 in large lots than in small, cheaper for cash than on time. Tbese values 

 are high enough to do no injustice to the dealer, and accurate enough to 

 .serve tbe object of the consumer. * * * The 'estimated values per 

 pound' in the above schedule are similar to those employed by Dr. 

 Goessmann and Professor Atwater in their recent reports." 



This method of estimating the commercial values of fertilizers has 

 been long practiced and has its uses, particularly as a forcible means of 

 illustrating frauds, and as the first step in tbe process of educating farm- 

 ers and manufacturers. People who are not familiar with chemical 

 terms understand dollars and cents, and are much more impressed by a 

 fertilizers " analyzing" 830 per ton when the price is $45, than by its 

 containing only six per cent, of soluble phosphoric acid when it ought to 

 have twelve. 



These calculations are, however, open to serious objections, with the 

 rest, because they not only difi'er very widely from the agricultural 



