FERTILIZER* 277

. completely precipitated, by addirjcr em xnr ybditt bclu.*?^ t * tit
supernatant liquid. L mon preup.utt f» ~* * \:r -i« t*- d #** ,^t
'ed by testing as before. Filtt r on paj t • a: J T\ ar , s *ir 4« It: r /t , . r
*xrnonmm nitrate sc/ation , * . Durmjrt' > ^i^ti IT T +.+» *c i*

®ss to the flask need m 11 e touplt ti !v n»' , »s ," i' + »^ >* *^ - 4-l' *i.
c^ the flask in whid- prenpitaa* n na,- \idi \\.it I i> ^%« ,i ti

^<s the precipitate on the tihir in i, piVntnitMi .I\M«^I^ ' \rlr"\ b
little as possible followed by Lrt \vuttT, ^K* '4 *i*» t e is 1,:* ^ t^

"V-ery thoroughly \\ith hot \vatu. Transfer tb !*'r»- -i1!/. -^ a: il
to a 250-cc beaker of nt^taLu* g! ^ 1» » .»tj' \ rn * t * *l ?
should not be greater than 100 « . \i j, >v n< -ur ' ,e ^ *j /.>ilr *-

-C5 acid, the reformation of tht yellow pret*jita » ^ n nu i* i Ji*^* r,

isolve the precipitate that finallj ft mis i v tht ,4dd,t *- ^ a Trm d^»p« f '

u.*fce ammonium hydroxide. Co<>t and add, TTV >' »i v j,r:J mifh \ "K* I

stirring, 25 cc of magnesia mixtim . Artcr 15 ^\ n ^< - a Is! ^1^:1 > <"MI 9 I :

^cicie (specific gravity 0.00- upial ,« oiJMkiit. «f t"1«» . ^t t, T~^ia \c * T J !

oluition, stirring as this is added. Oner ar ! :^\ \\ t> ** u d fi« F+T** I '

5- Filter and wash with dilute amn*( nil ir ! \drov»i* i TS* 1 L". t- I

y ^"ree from chlorides, as shown by auditing tf f va> i.r,o< \\'tTi '< *»• » j

adding silver nitrate solution. Dry tht Hilt:, j,nd pn*'I| ita**1 a,i 1 |

the latter to a porcelain eraubie, prev'oiir.y isnitid ar.d \irI0 nl I •

e -fc°he filter separately and transfer it.« ash, when write, to the rrur*b e \

lining the main precipitate. Ignite to w! ittne&i o* gravish vhiU ovo* I

»la,st lamp or Meker bumtr, weigh and calculate the per cent of \

us pentoxide. j

Itxxnetric Determination.'—Have the following ready: I

MohjMMte.—To each 100 cc of the molybdate
prepared for the gravimetric determination of 5 cc I
>n.oentrated nitric acid. The solution should be immediately
re rising.
) Standard potassium hydroxide I cc of which Is to
; of phosphorus. (Refer to equation (2} on . Part I.) This
» n.oarly free from carbonates as possible and is made as follows: Dissolve
r cent more than the calculated quantity for 1000 ce, dilute to 100 cc
add 1 cc of a saturated solution of barium hydroxide. Stopper the
. and allow to stand until the precipitate of barium carbonate has settled.
&n-fc and dilute to 1000 cc. Standardize by titration
using phenolphthalein. Adjust so that 1 cc is equivalent to 0.1 mg of
sjpttoras.
) Standard Hydrochloric or Nitric Add—This solution should be
vaJent in strength to the standard base. It should be from
ioxisly boiled and cooled water and it should be standardizes! by titration
ELS* the basic solution, using phenolphthalein as indicator.
h.o fertiliser is dissolved by either of methods {&), f», (/) or (g}, 276.
-h-od (e) is to be preferred if the material will yield to this treatment.
solution is to be diluted and filtered as already directed.