SoweremainedinParis,andwithourincomeincreased.Butwewereatthesametimeworkingunderincreasinglydifficultconditions.PierreCuriewasdoingdoubleteaching;andthatintheP.C.N.,withitsverylargenumberofstudents,fatiguedhimgreatly.Asformyself,IhadtogivemuchtimetothepreparationofmylecturesatSevres,andtotheorganizationofthelaboratoryworkthere,whichIfoundveryinsufficient.
Moreover,PierreCurie'snewpositiondidnotbringwithitalaboratory;alittleofficeandasingleworkroomwereallthathehadathisdispositionintheannex(rueCuvier)oftheSorbonne,whichservedasteachingquartersfortheP.C.N.Andyethefeltitabsolutelynecessarytogoaheadwithhisownwork.Infact,therapidextensionofhisinvestigationsinradioactivityhadmadehimdeterminethatinhisnewpositionattheSorbonnehewouldreceivestudentsandstarttheminresearch.Hethereforetookstepstofindlargeravailableworkingquarters.Thosewhohavetakensimilarstepsrealizethewalloffinancialandadministrativeobstaclesagainstwhichhewasthrowinghimself,andrealizethelargenumberofofficialletters,visits,andofrequeststheleastsuccessentailed.AllthisthoroughlyweariedanddiscouragedPierreCurie.Hewasobliged,too,constantly,tokeeptravelingbackandforthbetweenthelaboratoriesoftheP.C.N.andthehangaroftheSchoolofPhysicswherewestillcontinuedourwork.
Andbesidesthesedifficulties,wefoundthatwecouldnotmakefurtherprogresswithouttheaidofindustrialmeansoftreatingourrawmaterial.Fortunatelycertainexpedientsandgenerousassistancesolvedthisquestion.
AsearlyasPierreCuriesucceededinorganizingafirstindustrialexperiment,usingforitachanceinstallationplacedathisdispositionbytheCentralSocietyofChemicalProducts,withwhichhehadhadrelationsinconnectionwiththeconstructionofhisbalances.ThetechnicaldetailshadbeenarrangedverysuccessfullybyAndreDebierne,andtheoperationsbroughtgoodresults,eventhoughithadbeennecessarytotrainaspecialpersonnelforthischemicalworkwhichdemandedspecialprecautions.
Ourinvestigationshadstartedageneralscientificmovement,andsimilarworkwasbeingundertakeninothercountries.TowardtheseeffortsPierreCuriemaintainedamostdisinterestedandliberalattitude.Withmyagreementherefusedtodrawanymaterialprofitfromourdiscovery.Wetooknocopyright,andpublishedwithoutreservealltheresultsofourresearch,aswellastheexactprocessesofthepreparationofradium.Inaddition,wegavetothoseinterestedwhateverinformationtheyaskedofus.Thiswasofgreatbenefittotheradiumindustry,whichcouldthusdevelopinfullfreedom,firstinFrance,theninforeigncountries,andfurnishtoscientistsandtophysicianstheproductswhichtheyneeded.Thisindustrystillemploysto-day,withscarcelyanymodifications,theprocessesindicatedbyus.
Eventhoughourindustrialexperimentyieldedgoodresults,againourslenderresourcesmadeitdifficulttomakefurtherprogress.Inspiredbyourattempt,aFrenchindustrial,ArmetdeLisle,hadtheidea,whichseemeddaringatthatepoch,offoundingaveritableradiumfactorythatwouldfurnishthisproducttophysicians,whoseinterestinthebiologicaleffectsofradiumanditspossibletherapeuticapplicationshadbeenarousedbythepublicationofvariousinvestigations.Theprojectprovedasuccessbecausehecouldemploymenalreadytrainedbyusinthedelicateprocessesofthismanufacture.Radiumwasthenregularlyplacedonsale,atahighprice,itistrue,becauseofthespecialconditionsunderwhichithadtobemade,andbecause,too,oftheimmediateriseinthecostofthemineralsnecessarytoitsproduction.
Ishouldliketoexpress,here,ourappreciationofthespiritinwhichArmetdeLisleofferedtoco?peratewithus.Inanentirelydisinterestedmannerheplacedatourdispositionalittleworkingplaceinhisfactoryandapartofthemeansnecessaryforustouseit.Otherfundswereaddedeitherbyourselves,orcamethroughsubventions,ofwhichthemostimportant,accordedinbytheAcademyofSciences,amountedto,francs.
Itwasinthiswaythatwewereabletoutilizetheorewehadacquiredlittlebylittleinthepreparationofacertainquantityofradium,whichweusedconstantlyinourresearch.Theradium-bearingbariumwasextractedinthefactory,andIcarriedonitspurificationandfractionalcrystallizationinthelaboratory.InIsucceededinpreparingadecigrammeofchlorideofpureradiumwhichgaveonlythespectrumofthenewelement,radium.Imadeafirstdeterminationoftheatomicweightofthisnewelement,anatomicweightmuchhigherthanthatofbarium.Thusthechemicalindividualityofradiumwascompletelyestablished,andtherealityofradioelementswasaknownfactaboutwhichtherecouldbenofurthercontroversy.
Ibasedmydoctor'sthesis,presentedin,ontheseinvestigations.
Later,thequantityofradiumextractedforthelaboratorywasincreased,andinIwasabletomakeasecondandmoreprecisedeterminationoftheatomicweightas——oneacceptsnowthenumber.Isucceeded,too,jointlywithAndreDebierne,inobtainingradiuminthestateofmetal.ThetotalquantityofradiumIpreparedandgavetothelaboratory,inagreementwithPierreCurie'sdesire,amountedtomorethanagrammeofradiumelement.