ABSTRACT
Atthispointinourchronicle,itiseasytooverlookthattheelectron wasnotMillikan'sprogeny,butJJThomson's.Moreover,thestandard historyhasRutherford'splanetaryatomspringingfull-blownfroman inspiredrefutationofThomson's'plumpudding'atomicmodelthrough analysisofthefamousscatteringexperimentofGeigerandMarsden.In fact,Thomson'satom,ormoreproperlyhisresearchprogramgenerally, playedamuchgreaterroleinfosteringRutherford'striumphof1911than iscommonlysupposed.Thea-particlescatteringexperiment,too,hadits harbingerinJJThomson'sresearches,leadingThomson,asHeilbronputs it,'closeto,butstillsomedistancefromthecentralprincipleofatomic theory,thedoctrineofatomicnumber'[17-1].Indeed,intheultimateof ironies,oneofthemainargumentsforThomson'splumpuddingwasits supportofa-particlescatteringexperiments-experimentswhichsealed thefateofhismodel[17-2]!
