TheCongressofofferedusanopportunitytomakeknown,atcloserrange,toforeignscientists,ournewradioactivebodies.ThiswasoneofthepointsonwhichtheinterestofthisCongresschieflycentered.
Wewereatthistimeentirelyabsorbedinthenewfieldthatopenedbeforeus,thankstothediscoverysolittleexpected.Andwewereveryhappyinspiteofthedifficultconditionsunderwhichweworked.Wepassedourdaysatthelaboratory,ofteneatingasimplestudent'slunchthere.Agreattranquillityreignedinourpoor,shabbyhangar;occasionally,whileobservinganoperation,wewouldwalkupanddowntalkingofourwork,presentandfuture.Whenwewerecold,acupofhottea,drunkbesidethestove,cheeredus.Welivedinapreoccupationascompleteasthatofadream.
Sometimeswereturnedintheeveningafterdinnerforanothersurveyofourdomain.Ourpreciousproducts,forwhichwehadnoshelter,werearrangedontablesandboards;fromallsideswecouldseetheirslightlyluminoussilhouettes,andthesegleamings,whichseemedsuspendedinthedarkness,stirreduswithevernewemotionandenchantment.
Actually,theemployeesoftheSchoolowedPierreCurienoservice.Butneverthelessthelaboratoryhelperwhomhehadhadtoaidhimwhenhewaslaboratorychiefhadalwayscontinuedtohelphimasmuchashecouldin.Thisgoodman,whosenamewasPetit,feltarealaffectionandsolicitudeforus,andmanythingsweremadeeasierbecauseofhisgoodwillandtheinterestbetookinoursuccess.
Wehadbegunourresearchinradioactivityquitealone,butbecauseofthemagnitudeoftheundertaking,weweremoreandmoreconvincedoftheutilityofinvitingcollaboration.Alreadyin,oneofthelaboratorychiefsoftheSchool,G.Bemont,hadgivenustemporaryaid.AndtowardPierreCurieassociatedwithhimayoungchemist,AndreDebierne,preparatorunderFriedel,whoheldhiminhighesteem.AndreDebiernegladlyacceptedPierreCurie'sproposalthatheoccupyhimselfwiththeinvestigationofradioactivity;andheundertook,inparticular,thesearchforanewradioelement,whichwesuspectedexistedintheirongroupandinrareearths.Hediscoveredtheelementactinium.EventhoughhecarriedonhisworkinthelaboratoryofphysicalchemistryattheSorbonne,directedbyJeanPerrin,hefrequentlycametovisitusinourstoreroom,andwassoonanintimatefriendofours,andofDoctorCurieandthechildren.
Aboutthissametime,GeorgeSagnac,ayoungphysicistengagedinthestudyofX-rays,oftencametodiscusswithmyhusbandtheanalogiesonecouldexpecttofindbetweentheserays,andtheirsecondaryrays,andtheradiationsofradioactivebodies.Theyworkedtogetherontheinvestigationoftheelectricchargecarriedbythesecondaryrays.
Besidesourcollaboratorswesawveryfewpersonsinthelaboratory;however,fromtimetotimesomephysicistorchemistcametoseeourexperiments,ortoaskPierreCurieforadviceorinformation;forhisauthorityinseveralbranchesofphysicswasverywellrecognized.Andthentherewerediscussionsbeforetheblackboard,——discussionswhicharepleasantlyrememberedto-day,becausetheystimulatedaninterestinscienceandanardorforworkwithoutinterruptinganycourseofreflection,andwithouttroublingthatatmosphereofpeaceandcontemplationwhichisthetrueatmosphereofthelaboratory.