26 THE CONNECTICUT AGRICULTUEAL 



ton is |5 or more over the estimated value, it would be well tO' 

 look further. 2d, Comparisons of the estimated values and sell- 

 ing prices of a number of fertilizers will generally indicate fairly 

 which is the best for the money. But the " estimated value " is 

 not to be too literally construed, for analysis cannot always 

 decide accurately what is the form of nitrogen, etc., while the 

 mechanical condition of a fertilizer is an item whose influence 

 cannot always be rightly expressed or appreciated. 



TTie AgrlmiUural value of a fertilizer is measured by the benefit 

 received from its use, and depends upon its fertilizing effect, or 

 crop-producing power. As a broad, general rule, it is true that 

 Peruvian guano, superphosphates, fish-scraps, dried blood, potash 

 salts, plaster, etc., have a high agricultural value which is related 

 to their trade-value, and to a degree determines the latter value. 

 But the rule has many exceptions, and in particular instances the 

 trade-value cannot always be expected to fix or even to indicate 

 the agricultural value. Fertilizing effect depends largely upon 

 soil, crop and weather, and as these vary from place to place and 

 from year to year, it cannot be foretold or estimated except by 

 the results of past experience, and then only in a general and 

 probable manner. 



For the above first-named purpose of valuation, the trade-values 

 of the fertilizing elements which are employed in the computations 

 should be as exact as possible, and should be frequently corrected 

 to follow the changes of the market. 



For the second-named use of valuation, frequent changes of the 

 trade-values are disadvantageous, because two fertilizers cannot 

 be compared as to their relative money-worth, when their valua- 

 tions are estimated from difierent data. 



Experience leads to the conclusion that trade-values adopted at 

 the beginning of a year should be adhered to as nearly as possible 

 throughout the year, notice being taken of considerable changes 

 in the market, in order that dtie allowance may be made therefor. 

 It should be remembered that, in an Annual Report, the fluctua- 

 tions in ti*ade-value that may occur within the year cannot be 

 accurately followed, and the comparisons of estimated values are 

 mostly in retrospect. 



The valuations for 1883 were adopted in consultation with Dr. 

 Goessmann, Director of the Massachusetts Agricultural Experi- 

 ment Station, Prof. Cook, Director of, and Dr. Neale, Chemist to, 

 the New Jersey Agricultural Experiment Station, and have beeix 

 employed by these gentlemen in their official Reports for 1883. 



