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‘ 168 ` Bulletin No. 2/.9.
i A values from the analyses of fertilizers. Accordingly, to eoniply
i with the requirement of the law referred to, we have adopted
i p a system of relative values, based upon what we may term an
p * "index of relative value" computed from the analysis by 1nul—
T i tiplying the percentage of each essential ingredient found in
_ ~ y the analysis by a certain factor or "index," the sum of these
.   ` . products being taken as the "index of relative value." This
_ i ' i "indcx" will not stand in any necessary relation to the pres-
=   I . ent market price of the fertilizer. but docs give an expression
i   I i . of its relative value, under normal conditions.
    t i The following are the factors for computing the relative
    value indexes given in the tables of analyses;
    b » Available phosphoric acid in mixed fertilizers __.,.__,._.......,....,._.,_ 1.2
3 L `~ Available phosphoric acid in acid phosphates ............................ 1.0 1
  Insoluble phosphoric acid in mixed fertilizers .......................i.... - 0.4
 \- . lnsoluble phosphoric acid in acid phosphates ...i........................ nothing _
l   1 Phosphoric acid in fine bone ...............l.............,.A.............................. 0.8
1 V Phosphoric acid in medium bone .........,............... i .....l...,................., 0 .6
I   . Nitrogen in all fertilizers ........................_..........................,,...,........... 3.5
  Potash from sulfate, in all fertilizers .......................,...........,............ 1.2 »
` ‘   py I Potash from inuriate, in all fertilizers ,,__,_...___,___..___,.__.,._.,_.l..,...,..... 1.0
n     As an example of how to make the calculation, suppose the
“ gl analysis shows that a fertilizei; contains:
`   \ 8.40 per cent. of available phosphoric acid.
    ` 4.75 per cent. of insoluble phosphoric acid.
; i_ § 1.58 per cent. of nitrogen. ·
E   1.24 per cent. ofpotash from muriate.
: —.  
    l The index of relative value will lie calculated as follows:
.. fi gl  i 1.2 times 8.40 is ................................................ 10.1
.   l 0.4 times 4.75 is ................................................ 1.9
  lt  l , 21.5 times 1.58 is .............,...........i...................... 5.5
      1.0 umm 1.34 is ..._....,,....__.._._,..__.._.__................ 1.2
i i     Sum .................... 18.8 \
  ·` 'l`herefore. the index of relative value foi· this fertilizer  
;_.Q·;z.    ies. .
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