348 



VALUATION AND PURCHASE 



[chap. 



such values and compare the actual price with the 

 estimates formed on that basis. In such comparisons it 

 is not necessary to know the exact current unit value of 

 each constituent, as long as a due proportion between 

 them is preserved, and it will be sufficiently accurate 

 to use what are approximately the rates prevailing in 

 1908, viz.: — 14s. per unit for nitrogen, is. 3d. per unit 

 of insoluble and 2s. per unit of soluble phosphate, and 

 4s. per unit of potash. 



For example, fish and meat guanos were offered as 

 follows : — 



Table CI. — Estimated Value of Fertilisers. 



Clearly, among these manures No. 3 is much the 

 cheapest fertiliser, while No. i is exceptionally dear; 

 unless there was something wrong with the mechanical 

 condition of No. 3 there is nothing in the relative 

 nature of the fertilisers to prevent the farmer taking 

 advantage of its lower cost. 



The example just quoted, which was derived from 

 actual experience, shows the importance to the farmer 

 of a careful consideration of the analysis of fertilisers on 

 sale ; too much stress cannot be laid on the necessity of 

 conducting all transactions regarding fertilisers on such 



