The Middlebury register. [volume] (Middlebury, Vt.) 1850-1882, 1875-05-25
AarifnltaraI Dspartm tnt.
oHpucIEp BY ALBERT CHAPMAN
Popular Science"

Any reader of our Eastern agricul-
tural papers sees frequent aiiusions
ma lie to p~hosphates and superphos-
pilates. The former word merely
means decomposed bones or the car
Donate Of lime. Superphosphate Is a
scientific preparation of this material
for fertilizing, and is two parts bone,
one part sulphuric acid, and three parts
water.-Ex.
We find the above scrap of mis-in-
formation in an agricultural" ext
change. Nowadays chemistry Is
taught in all our academies and many |
of our public schools; yet 1t is perhaps
asking too much TO require that. editors |
of agricultural papers should know
anything about a science more closely
interviewer with successful agriculture
than any other. Certainly we would
not advise an agricultural editor who,
at a county fair, had to inquire which
were the Shorthorns and which the
Jerseys, to make chemistry his first
study. But would 1t be "2 mulch" as
the lamented A. Ward would say, to
expect that an editor. evidently in total
oblivion as regards the first lines of
agricultural chemistry, would merci-
fully forbear. attempting to give in
struction therein, either at first or
sooond hand?
The first sentence In the above ex-
tract is probably correct. 1t is ONE
thing to have the exordium of a
scientific lecture in accord with facts.
But the two succeeding sentences con-
tain six very stupid errors, and not a
single approximation to the truth.
"~Phosphate' does not mean decompos-
ed bones; it does not mean carbonate
of lime. "Superphospate" is not a
scientific preparation of carbonate of
bone it contains no sulphuric acid and
no water.
Perhaps. it may bc as well not to stop
here, but to say briefly lust what
''phosphates" and "superphosphates'
of lime are. They are both of them
compounds of an acid called phosphoric
acid, with lime. Phosphoric acid is
itself a compound of phosphorus
(Which we are all familiar with as
being used in the tips of friction
m%atches) with the oxygen of common
air. Phosphoric acid is produced when
PHOSPHORUS is burned. In a pure form
it appears as a white powder. which,
dissolved in water, has a very sour
taste. Phosphoric acid combines with
other bases besides lime, and these
compounds are all called "phosphates;''
q fact evidently unknown to the writer
Of the above extract. With lime ii
makes three distinct compounds or
phosphates, as follows:
Three parts lime, one part phosphoric acid.
1.-Two parts lime, one part phosphoric acid.
3.-One part lime, one part phosphorus acid.
The first of these phosphates, or
"three-lime phosphate" is the phos-
plate which is found in bones and in
the phosphate minerals used for max
ing fertilizers; such as the South
Carolina phosphate and the phosphate
rock called ''apatite." 1t is insoluble
in water, and consequently useless as q
fertilizer until it is in some way changed
so that water can dissolve it, since
plants always take their food in a fluid
form.
The second compound of phosphoric
acid and lime, or ''two-lime phosphate
is a somewhat rare substance, and is
also nearly insoluble in water.
In order to make the phosphate Of
lime in bones and mineral phosphates
useful asa fertilizer, it must be made
soluble in water and this is done by
changing 1t into the third compound
or "one-ime phosphate" called also
"superphosphate," and Soluble phos'
phate." To effect this it is necessary
to deprive the ''three-lime phosphate
of two parts of its lime, which is done
by the use of sulphuric acid, otherwise
called ''oil of vitriol." When sulphurit
acid is added TO ground bones OIL
~pulverizesl mineral phosphate of lime
-"three-lime phosphate, lit takes
away from it two parts of the lime
which IL contains, and unites with tina
line to form a substance called ''sul
phate of lime" This substance is also
called ''plaster, or Gypsum" which
most farmers are familiarlwith. When
the mixture is complete, the proper
proportions having been used, the mass
consists of one-lime or soluble phos'
phate. sulphate of lime and the Other
substances which were contained in
the bones or the mineral. About one.
half the material of Done consists Of
"three-lime phosphate" the rest being
mostly animal matter containing
nitrogen, which is also valuable as q
fertilizer.
The 'superphosphate" which results
from the above described process con.
sists simply Of n part of phosphoriC
acid and one part of lime. 1t does no,
contain any 'bone," for that has been
decomposed. 1t does not contain any
sulphuric acid, for hat is combined
with the lime to make sulphate Of lime,
Neither does II contain any water. II
is Just simply lime and phosphoric
acid, united together, in equal parts,
by weight.
But the whole mass which is what IL
sold as n farfilizar updar tba oou-...l