duringhecourseofmyresearch,ihadhadoccasionoexaminenoonlysimplecompounds,salsandoxides,bualsoagreanumberofmineralscerainonesprovedradioacive;hesewerehoseconaininguraniumandhorium;buheirradioaciviyseemedabnormal,foriwasmuchgreaerhanheamounihadfoundinuraniumandhoriumhadledmeoexpec

hisabnormaliygrealysurpriseduswhenihadassuredmyselfhaiwasnodueoanerrorinheexperimen,ibecamenecessaryofindanexpnaionihenmadehehypohesishaheoresuraniumandhoriumconaininsmallquaniyasubsancemuchmoresronglyradioacivehaneiheruraniumorhoriumhissubsancecouldnobeoneofheknownelemens,becausehesehadalreadybeenexamined;imus,herefore,beanewchemicalelemen

ihadapassionaedesireoverifyhishypohesisasrapidlyaspossibleandpierrecurie,keenlyineresedinhequesion,abandonedhisworkoncrysals(provisionally,hehough)ojoinmeinhesearchforhisunknownsubsance

wechose,forourwork,heorepichblende,auraniumore,whichinispuresaeisaboufourimesmoreacivehanoxideofuraniumsincehecomposiionofhisorewasknownhroughverycarefulchemicalanalysis,wecouldexpecofind,aamaximum,percenofnewsubsanceheresulofourexperimenprovedhaherewereinrealiynewradioaciveelemensinpichblende,buhaheirproporiondidnoreachevenamillionhpercen!

hemehodweemployedisanewmehodinchemicalresearchbasedonradioaciviyiconsissininducingseparaionbyheordinarymeansofchemicalanalysis,andofmeasuring,undersuiablecondiions,heradioaciviyofallheseparaeproducsbyhismeansonecannoehechemicalcharacerofheradioaciveelemensoughfor,foriwillbecomeconcenraedinhoseproducswhichwillbecomemoreandmoreradioaciveasheseparaionprogresseswesoonrecognizedhaheradioaciviywasconcenraedprincipallyinwodifferenchemicalfracions,andwebecameableorecognizeinpichblendehepresenceofaleaswonewradioaciveelemens:poloniumandradiumwea

ouncedheexisenceofpoloniuminjuly,,andofradiumindecemberofhesameyear

inspieofhisreivelyrapidprogress,ourworkwasfarfromfinishedinouropinion,herecouldbenodoubofheexisenceofhesenewelemens,buomakechemissadmiheirexisence,iwasnecessaryoisoehemnow,inourmossronglyradioaciveproducs(severalhundredimesmoreacivehanuranium),hepoloniumandradiumwerepresenonlyasraceshepoloniumoccurredassociaedwihbismuhexracedfrompichblende,andradiumaccompaniedhebariumexracedfromhesamemineralwealreadyknewbywhamehodswemighhopeoseparaepoloniumfrombismuhandradiumfrombarium;buoaccomplishsuchaseparaionwehadohaveaourdisposiionmuchrgerquaniiesofheprimaryorehanwehadiwasduringhisperiodofourresearchhawewereexremelyhandicappedbyinadequaecondiions,byheckofaproperpceoworkin,byheckofmoneyandofperso

el

pichblendewasanexpensivemineral,andwecouldnoaffordobuyasufficienquaniyahaimeheprincipalsourceofhismineralwasasjoachimshal(bohemia)whereherewasaminewhichheausriangovernmenworkedforheexracionofuraniumwebelievedhawewouldfindallheradiumandaparofhepoloniuminheresiduesofhismine,residueswhichhadsofarnobeenusedaallhanksoheinfluenceofheacademyofsciencesofvie

a,wesecuredseveralonsofheseresiduesaanadvanageousprice,andweusediasourprimarymaerialinhebegi

ingwehadodrawonourprivaeresourcesopayhecossofourexperimen;erweweregivenafewsubvenionsandsomehelpfromousidesources

hequesionofquarerswasparicurlyserious;wedidnoknowwherewecouldconducourchemicalreamenswehadbeenobligedosarheminanabandonedsoreroomacrossacourfromheworkroomwherewehadourelecromericinsalionhiswasawoodenshedwihabiuminousfloorandagssroofwhichdidnokeepherainou,andwihouanyineriorarrangemensheonlyobjecsiconainedweresomewornpiables,acasironsove,whichworkedbadly,andhebckboardwhichpierrecurielovedouseherewerenohoodsocarryawayhepoisonousgaseshrownoffinourchemicalreamens,sohaiwasnecessaryocarryhemonousideinhecour,buwhenheweaherwasunfavorablewewenonwihheminside,leavinghewindowsopenaviewofheexracionofradiuminheoldshedwherehefirsradiumwasobained