Eventhoughhewasverymuchabsorbedinthepreparationofhiscourse,andoftenill,myhusbandcontinued,nevertheless,toworkinthelaboratory,whichwasbecomingbetterandbetterorganized.Hehadalittlemorespacenow,andcouldreceiveafewstudents.IncollaborationwithA.Laborde,hecarriedoninvestigationsinmineralwatersandgasesdischargedfromsprings.Thiswasthelastworkhepublished.
Hisintellectualfacultieswereatthistimeattheirheight.Onecouldbutadmirethesuretyandrigorofhisreasoningonthetheoriesofphysics,hisclearcomprehensionoffundamentalprinciples,andacertainprofoundsenseofphenomenawhichhehadbyinstinct,butwhichheperfectedduringthecourseofalifeentirelyconsecratedtoresearchandreflection.Hisskillinexperiment,remarkablefromthebeginning,wasincreasedbypractice.Heexperiencedthepleasureofanartistwhenhesucceededwithadelicateinstallation.Heenjoyed,too,devisingandconstructingnewapparatus,andIusedjokinglytotellhimthathewouldnotbehappyunlesshemadeatleastanattemptofthiskindonceeverysixmonths.Hisnaturalcuriosityandvividimaginationpushedhimtoundertakingsinveryvarieddirections;hecouldchangetheobjectofhisresearchwithsurprisingease.
Hewasscrupulouslycarefulofscientificprobityandofcompleteaccuracyinhispublications.Theseareveryperfectinform,andnonethelesssointhosepartswhereheappliesthecriticalspirittohimself,expressinghisdeterminationnevertoaffirmanythingthatdoesnotseementirelyclear.Heexpresseshisthoughtonthispointinthefollowingwords:"Inthestudyofunknownphenomena,onecanmakeverygeneralhypothesesandthenadvancestepbystepwiththehelpofexperience.Thismethodofprogressissurebutnecessarilyslow.Onecan,onthecontrary,makedaringhypothesesinwhichhespecifiesthemechanismofphenomena.Suchamethodofprocedurehastheadvantageofsuggestingcertainexperiments,and,aboveall,offacilitatingreasoningbyrenderingitlessabstractthroughtheemploymentofanimage.Butontheotherhand,onecannothopethustoconceiveacomplextheoryinaccordwithexperiment.Theprecisehypothesisalmostcertainlyincludesaportionoferroralongwithaportionoftruth.Andthislastportion,ifitexists,formsonlyapartofamoregeneralpropositiontowhichitwillbenecessaryintheendtoreturn."
Moreover,eventhoughheneverhesitatedtomakehypotheses,heneverpermittedtheirprematurepublication.Hecouldneveraccustomhimselftoasystemofworkwhichinvolvedhastypublications,andwasalwayshappierinadomaininwhichbutafewinvestigatorswerequietlyworking.Theconsiderablevogueofradioactivitymadehimwishtoabandonthisfieldofresearchforatime,andtoreturntohisinterruptedstudiesofthephysicsofcrystals.Hedreamedalsoofmakinganexaminationofdiversetheoreticalquestions.
Hegavemuchthoughttohisteaching,whichconstantlyimproved,andwhichsuggestedtohimideasonthegeneralorientationofstudiesandonmethodsofteaching,whichhebelievedshouldbebasedoncontactwithexperienceandnature.HehopedtoseehisviewsadoptedbytheAssociationofProfessorsassoonasitwasformed,andtoobtainthedeclaration"thattheteachingofthesciencesmustbethedominantteachingofboththeboys'andgirls'lycees.""But,"hesaid,"suchanotionwouldhavelittlechanceofsuccess."
Butthislastperiodofhislife,sofecund,was,alas,soontoend.Hisadmirablescientificcareerwastobesuddenlybrokenattheverymomentwhenhecouldhopethattheyearsofworktocomewouldbelesshardthanthosewhichhadpreceded.
In,quiteillandtired,hewentwithmeandthechildrentospendEasterintheChevreuseValley.Thoseweretwosweetdaysunderamildsun,andPierreCuriefelttheweightofwearinesslighteninahealingreposeneartothosewhoweredeartohim.Heamusedhimselfinthemeadowswithhislittlegirls,andtalkedwithmeoftheirpresentandtheirfuture.
HereturnedtoParisforareunionanddinnerofthePhysicsSociety.TherehesatbesideHenriPoincareandhadalongconversationwithhimonmethodsofteaching.Aswewerereturningonfoottoourhouse,hecontinuedtodevelophisideasontheculturethathedreamedof,happyintheconsciousnessthatIsharedhisviews.
Thefollowingday,thethofApril,,heattendedareunionoftheAssociationofProfessorsoftheFacultiesoftheSciences,wherehetalkedwiththemverycordiallyabouttheaimswhichtheAssociationmightadopt.AshewentoutfromthisreunionandwascrossingtherueDauphine,hewasstruckbyatruckcomingfromthePontNeuf,andfellunderitswheels.Aconcussionofthebrainbroughtinstantaneousdeath.Soperishedthehopefoundedonthewonderfulbeingwhothusceasedtobe.Inthestudyroomtowhichhewasnevertoreturn,thewaterbuttercupshehadbroughtfromthecountrywerestillfresh.