IlY W. 1'. JOIIISSES A S U J. IIU'ITI~X.
111 the COIIMO af it I l i ~g C iiuiiibcr of tletcriiiiiintions of iirrlilitlinlcnc 1iy the ClOliiinii-Sinit11 inet~hotl,~ tlic results olitriinctl iverc nlwnys too Iow.2 In tlicsc exlicrinicnts con1 gns freed froin nnplitliulcne or nir wns ~inssctl togrtlier with ~inplit~inlciie tliroiigli lJ-t.iilics containing picrie iwid soliition, whicli \vuru \veiglictl bcforo irntl nftcr tlic c x ~~r i m c i i t . Xierinoycr' tiIJtaiiictl siiiiilur ~vsiilts iiitlcpciidcntly. Wlicn it ~v n s nttcniptctl fa cletcriiiiiic tlic lricruto forincd by fiIhriiig, cvashing with water, nnd clryiiig in n tlcsiccntor, the rcsulfs wwu lower still : 82 pcr cent. of tlic nupl~tlinlciic in aiccriitio. I t ~vns, Iio\r.ovcr, oIisorvcd tliiit nccumtc results \vcru obtnincd \vIicii the wnnliiiig bottles coiitniiictl not only IL saturated solution of picric ncitl, but some iintlissolvetl picric ncitl us well. , 'J'lic mutlrocl used4 svns n s follows : 2560 C.D. of n sntiirntctl noliitioii of Iiicric clcitl is cvnl)orntrtl to i ~l ~o i i t 150 c.c., niitl trunsfcrrcd wliilst hot to t w o gars-wasl~ing bottles. l'lio c o d gw, which Iins bccn frcctl Iicforclinnd froin trir, c ~riiogeri, Iiydrogeir siilpliidc, nnd nininonin, is pnssctl tijrcJiigli t ~i c bottles tit, r i rntc of 3 0 4 0 litres nii ~ioiir. \Vhcii n fnir tpzilitity of picrntc lins been foriiictl in tlic lirst. I~ot tlc, the gnu-iiiotcr is rend iuitl 1110 picric ncitl diitioii togcthrr with the piornto urc trnnsfcrretl n 250 e x . Ilusli. The bot,tlcw nix! tvasl~ctl wit11 \vutcr, wliiuh is ncltlcd to llio solutioii, iwtl thu lnttcr is iiiudc 1111 to 250 t x . with wntcr nntl licntctl in the closccl flnslc for 11df iin hour ut W C., iriitl stinlien fioiu tiiiiu to time, in order to dissolvo tho pieric noid. Tlic coolctl solution is liltcrcd a i d 25 o x . of tlic 1iItrntc IIW titrntctl by n . solrrtioii of potnssiuin liydrositlc of liiitiwii strciigtli, using litinus 11s indicntor ; 25 C.C. of tho originnl solution nro d s t ~ titrntctl. Yroai tlio tlitIorcncc, tliu clunntity of trbsorIJcc1 nuphtl~nlcno niriy be cnsily cnlclllntcd. Tlic rcsiilts obtuincd \vcro ns follows :-.