~
].'or this ~iiirpose 0.0164 grnmn. of ciilcinru phosplliitc eontitiriing .tg.!iI) ycr cent. of IB20, wcrc disaolvcd in n little iiitric i:cicl; tlie ncicl wns tlicn neutrnliaccl hy nninioiiiiini Iiydmte ntid t i slight CSCCSB of ncctic ticid :tdtlcd. Tlic nolution wns tlmi rniiclc up to BOO cc. 'I'lte stnndiircl solution of XnJil'O,. 12 1I2O \vns Inntlc iip by dissolving 10*203 grnis. of thc socli!irnphospltute contnining 19.60 per cent. of P,OS in writcr nncl rniikiltg tip to 11 litre; this solution therefore contiiirwtl 2 grins. 1 ; 0 , per litrc, nntl \vns tliercforc tltc siinic strciipli its the ciilciiini 1il1oapliiitc aolution. s0111t;on of uriiiiiiiiii 1iitr:itc cotttitining 35 grnts. Iwr litrc \vns prcpnrcd nntl riiti froni II liurettc into sc~iiinitc :In CV. of tlic iilrovc solntioiis, in tlic niitnncr tlc~crilictll wit11 tlic following resnlts :-50 cc. of tlieciilcitirn pliosplintc solution rcqiiircil l9*HO cc. of nniniuni soliition. 50 cc. of the sotliiiiti ~~liosliliiitc oht ti on rctliiirctl 20.83 cc. of tinininni solntio~i. 'l'liuri tlic unininni solution, if stiinilnrdiscrl Iiy ~otliiini ~ilicirpl~ittc., ~voiilti give too low resiiltr wlicn wctl for cstiniiititig ciilcinni phospliiitcs. 'I'lins if tlio citlcinn~ pliosphiite coutiiinctl-50 Ircr cent. of 1'&, the error woitlil be ?*51 1wr cent. 11) per cent. of I'lOi the error woiiltl bc n-Sn l i i ~ cent. Tlic urnninnt solntioii (stiintlitnli~nl by riicitns of ciilciiiin pliosphi~tc) WIII ttictt cotitnistctl iignirist tlic gnivinictric 1imccsa for crtitniiting ~iliospliiitcs. For this ~inrposc iituilyses wcrc tniitlc with sritnples of cnlcinnt pl~ospl~iitc, first by prccipitiiting liy iitntnoninni niolylicliitc, rind finiilly cstinintiiig 11s hfg.J'207 uiitl nlso Iiy titnition with nntuiiun solntioo. 'I'ltc following results were olitainctl with two sanqilcs of ciilcinni phosplinte :-
---~m -t w t t i q ? cl r I*:[): I ('titciiiin i Cii1viuiii fonnd. 1 ~l'lloa~llluto (1). i I'hos~rlllitu (2). d. 11. AIICII. 11' . Jlrrflft.