ItmaybeeasilyunderstoodhowdeeplyIappreciatedtheprivilegeofrealizingthatourdiscoveryhadbecomeabenefittomankind,notonlythroughitsgreatscientificimportance,butalsobyitspowerofefficientactionagainsthumansufferingandterribledisease.Thiswasindeedasplendidrewardforouryearsofhardtoil.
Thesuccessofthetherapydepends,ofcourse,onthepreciseknowledgeofthequantityofradiumwhichisused,sothatthemeasurementsofradiumareasimportantforindustryandformedicineasforphysicochemicalresearch.
Consideringalltheseneeds,acommissionofscientificmenofdifferentcountrieswasformedwhoagreedtotakeasabaseaninternationalstandard,formedofacarefullyweighedquantityofpureradiumsalt.Secondarystandardswerethentobepreparedforeachcountry,andcomparedtothebasicstandardbymeansoftheirradiation.Iwasappointedtopreparetheprimarystandard.
Thiswasaverydelicateoperation,astheweightofthestandardsample,quitesmall(aboutmilligrammesofchloride),hadtobedeterminedwithgreatprecision.Iperformedthepreparationin.Thestandardisathinglasstube,ofafewcentimetersinlength,containingthepuresaltwhichwasusedforthedeterminationofatomicweight.ItwasacceptedbytheCommissionandisdepositedintheInternationalBureauofWeightsandMeasuresatSevres,nearParis.Severalsecondarystandards,comparedwiththeprimaryone,havebeenputintoservicebytheCommission.InFrancethecontrolofradiumtubes,bythemeasurementoftheirradiation,takesplaceinmylaboratory,whereanyonemaybringtheradiumtobetested;intheUnitedStatesthisisdoneintheBureauofStandards.