rip11Iic*rit.io1is, I)ut t,lic utitlcrlyiiig priliciples of these arc not nrglrctcd. l'lic coiiil)ciisrit,ion ~rict~hod, IiiilIinnil)iiictrr rind cripillury tube nictliods, hydrogeu cells, qiiitiIiy(lrmc, oxygen, rind other elcctrodcs lire rlciirly tlcscri1)ctl :inti t.licir uses csplriiricd. Coiidit,ione nrp givcli for tlic potcnt,ioiiietric dcteriiiinntion of nliiiost. iqwy elr~iicnt riiitl ~i i n i t y rridiciils. Thcii the Irtst, p i r t of t-hi! I d ; tlciils with tcclinicril prodiicts, iiiriiuiy rilloys, ores r i n d ~iiiiicruIs, nliiiost rill of whicli CIIII he siit.isfiic:torily riiiiilyscd by t,hesc nictliods. TIir tcbst is clcrir u l i t l tindcrstnnd;il)le iiiid the stiideI1t ivIi,i II:IH worltrtl t Iirortgli t lie book would ccrtninly ltiive II tliororigli griisp of I)otciitioiiiet,ric nict,liods and t Iwir potciit-iiilit ivs. It. Illis I l t w i l i o frisllioiiiililc to c.iilti\vite ccrtniri I~rii~iclirs of i.hvniist.ry riiitl ripply t Iiriii t,o the ~holo fit.ltl, 111iic!11 like II Iiottiwo~irithic system of inctliciiie ; Iiiicro-iiirtliotls i i t d pot~nt~iorr~etric iiictliotls illiistrntc tliis t i:iitlciicy. 'Jlicre lire Iiiritiy wnys of dctcrniining tilost t h i w t , s ; the oiic t,o I)c soiiglit is tlic h s t one r ~t i t l t,licrc is 110 ~irt.irc i l l doing I J ~ 111i clcctricnl inethod or ii ttiic.ro-itie!t.lio(I whiit ciin be iiiore cnsily dono by, H I I ~, 1111 orclinriry volunictric one. l.'otenbiollictric liriicessrs itre vwy vriliirt t)lc for certiiirl cstiinntioiis ; tliis Iinok is v~iluiil)lc I~cceiisc it I i e l p 11s to under-Ftiintl tliciii niid t,o know ' for wliich pitrposccs these riietliotls nre the best.