Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1853-12-31

and other substances remain The fltrate eyaporated
and il necessary, fltrated then boiled anc
mixed, when yet hot with strong ammonia will, oy cool
, ing, leave crystals Of molybdate of ammonia
solution of these crystals in water fur
nishes the above -mentoned resgsnt.
The effect of the molly OF ammonia on phosphorc
acid and its salts solution which has been acduaed
by nitric acid msnfests itself first in the forming Of
white precptate Of acid which Is redissolyed
however in the of nitric acid present The liquid
then yellow color and depostes yellow pre-
cpitate of crystalline structure the formation OF which
| is accelerated by heating.
This precpate consists of about three Of phos
phoric acid very small quantity Of ammonia, and,
taking the whole rest of acid which united
TO each other in yet doubtful. II is easily So
uble in ammonia and OF phosphates insoube
however, in hydrochloric or nitric acid.
These conditions demonstrate at once that the appca-
ton of this method is especially appropriated to the
tracing of small quantities OF phosphorus acid as IN
soils In this OF phosphaes, IN which the
formed precpitate could be dissolved is to be feared
the danger overlook precpitate, which consists
in its whole quantity of substances used :o- precipitation
with small portion of the substance watch 3 the object
| in search
Direct experiments to test the sensbiity OF this re-
agent made, and the following results obtained
BY iissolving grammes of crystalized phosphate OF
soda, which contain gramme Of phosphoric acid IN 20
grammes of water solution was obtained which con-
tanned IN all its parts l-3Oh OF its weightoi Phospho-
| rc acid.
With this normal-liquid different other solutions
(weighng about an ounce) were then made by diutng
the former with water and suitable quantity OF nitric
acid the respective contents Of phosphorus acid OF which
were 1300th 000th l6 000th liz 00Oh, LA OoOth
/ LAS, 050th, 1886 000th, 1-l9e 000th.
After molybdate OF ammonia being added and the
whole heated, Las, 000th $50 0ooth Of the dinon
created distinctly visible precpisate. The 1875, oooth
dution formed after few days little preaipate which
did not appear at tho 1-l92 000th diluon.
Experiments performed in the same mode, differing
only with regard to the normaliqud, which was diluted
with concentrated solution of soil (Which did not con-
tain appreciabe quantity Of phosphorc acd in nitric
| of wi
results 14S 000th or 150 000h diution caused
Immediately distinct precipitation, 49,, oOOth after
few days, and 1892, 900 none at all.
Organic matter iron, clay, lime, and all those sub
which extracted by the aid Of nitric acid from
SOIL had exercised the least influence on this
action.
After these advanced remarks, the last but most i'm
portant point be considered is finally toe manner in
which the above mentioned results Of observations can
be applied for the recognition and the quantatiye deter
minaon of the phosphoric acid in soils distinctly as
the farmer needs knowing it.
The solution Of this point leaves now hardly any dim
cuities
We know By analyses of Gregory Way, Boussingault
and Lebig that wheat crop Of 80 bushels at 81 bs
contains Of
Grain 9s4 lbs containing Of phOsphoric acid 10 Q lbs
Straw $500 lbs = "a lbs
Chat 400 lbs. . Il lbs
Total amount of phosphoric acid oB.5 lbs
If take crop of 80 bushels at GO lbs. for an
average crop, which wheat soil ought to produce,
and to which any wheat soil be improved, then
it is necessary above mentioned that it must contain
at least 265 bs or will say, 80 lbs Of phosphoric
acid if it shall be able TO produce the average crop
The weight Of average Of soil one foot deep is
1000 TONS 5000 900 pounds, according to the mean
specific gravity of sixteen varieties of soil dried in The
air, ascertaned by Dr. Krocker which 24l, land
not $4,000 lbs, stated by Major j. E. Lee-Prof
Booths authority.)
These two statements show the way IN which
soils ought TO be treated for detecting the presence and
at the time the approximate quantity Of phosphorc
acid in them. If 5000 000, 900 lbs Of soil one
acre. ought 70 contain 30 lbs of phosphoc acid to
duce fair crop Of wheat then every part of this mass
ought TO contain 1900 00Oh Of phosphoric acid or, II
dissolve the phosphoric acid in certain quantity OF
earth by solvent of equal weight the obtained solution
will also contain 1900 000th of phosphorc acid, or by
evaporating it 18th solution will be obtained which
contains l50 000h of phosphoric acid amount which
can be detected by molybdate of ammonia as above
: stated.
For soils the convenient quantity Of earth to be
taken for analysis is about Baths Of pound which IS TO
be treated with the quantity Of water calculated
with nitric acid and be heated in waterbath for
time The solution ought be itraed evaporated
10 18th, fltrated again. then about ounce IS left
and tested by mcybdate Of ammonia If visible prec
pat:on takes place then 80 IBIS Of phosphorc acid exist
at least in the examined so-60 lbs of phosphoric acid
if evaporated to one-haf 90 lbs of phosphoric acid if
evaporated 34ths 100 lbs Of phosphoric acid il not
at all evaporated, and
The whole process takes If performed in practice,
about two hours in which time several different soils
be treated in the way Of time
which will not be too costly for the chemist
I