Vermont watchman and State journal. [volume] (Montpelier, Vt.) 1836-1883, 1880-06-30

II will here be seen that the tri-calcic phos
phate (Which is the form in which it exists
in bones and minerals) consists of one part
of phosphoric acid and three parts of lime
This is the so-called insoluble phosphate,
but as in natural soils it is the only form in
which phosphate of lime primarily exists,
and as plants can extract it from such soils,
it must be clear that it is not totally insolu.
BILE, even in this form. This phosphate is
called three-lime phosphate" because it
has three parts of lime to one of phosphoric
acid. When it is ground fine and applied
TO the land it comes in contact with the
water of the soil, which always contains
carbonic acid. This acid acts upon the
mineral and takes away one part Of the lime
Corning carbonate of lime), and leaves the
phosphate of lime in new form,-the BIZ
cacic or twolime form, which is composed
of one part of phosphoric acid, two parts of
lime, and one part of water Water has
taken the place of the one part of lime cap
tured by the carbonic acid of the soil water.
This is what happens when Underground
bones or mineral phosphates are mixed with
the soil for fertilizing purposes, and we may
well suppose that the same action goes on,
though more slowly, upon the phosphate
rocks, gravel and sand, that exist in all nat
urally fertile soils. In this way the demand
of the natural vegetation for phosphoric
acid is supplied. But when we, in agricul-
ture, call for larger supply of this sub
stance as food for our cultivated crops, the
natural action of the water and carbonic
acid of the soil is not sufficient to supply it
fast enough. Probably all the naturally
good soils of Vermont have large store of
both phosphoric acid and potash in them
but the transformations by which they are
naturally made available are not rapid
enough to supply the demands of the re-
peated crops which we take off the land
If, instead of distributing the finely ground
bone or rock phosphate over the land, to be
acted upon by the saltwater as above ex-
planned, we put it into box, and upon it
use, in place of the mild carbonic acid Of
the saltwater, the powerful " oil of vitriol,"
or sulphuric acid, mixed with water, we can
at once transform the three-lime (tri-calcic)
phosphate of the bones or the mineral into
the so-called soluble or mono-cacic Zone
lime) phosphate. The sulphuric acid, in
stead of being satisfied, like the carbonic
acid, with one part of lime, takes away t,co
parts, replacing them with two parts Of
water. This is the kind of phosphate we
are supposed to buy in our commercial
supeyphosphates made by Bradley and 9TH
ers. This is what they aim to make, and
what, to a great extent, they succeed in
making. They do it because (and only be
cause) the chemists in making their analy-
SEES which are published in all the agricul-
tural papers, assign very much higher
value to this one-lime phosphate than they
do to the two-lime and the three-lime kinds.
The following are the prices at which these
phosphates are estimated in the analyses of
the Connecticut Experiment Station at the
present time. The table, as given in the
report of the station for 1873, page 10, is as
follows:
TRADE VALUES FOR 1879.
acid olul Ia lin IL A n,