Thelabourofthe12hours’working—dayisrepresentedbytheremaining93/5articles。Sincethepriceofthelabour—powerisfiveshillings，6articlesrepresentthenecessarylabour—time，and33/5
articlesthesurplus—labour。Theratioofthenecessarylabourtothesurplus—labour，whichunderaveragesocialconditionswas5:1，isnowonly5:3。Thesameresultmaybearrivedatinthefollowingway。Thevalueoftheproductoftheworking—dayof12hoursistwentyshillings。Ofthissum，twelveshillingsbelongtothevalueofthemeansofproduction，avaluethatmerelyre—appears。Thereremaineightshillings，whicharetheexpressioninmoney，ofthevaluenewlycreatedduringtheworking—day。Thissumisgreaterthanthesuminwhichaveragesociallabourofthesamekindisexpressed:twelvehoursofthelatterlabourareexpressedbysixshillingsonly。Theexceptionallyproductivelabouroperatesasintensifiedlabour;
itcreatesinequalperiodsoftimegreatervaluesthanaveragesociallabourofthesamekind。（SeeCh。I。Sect2。p。44。）Butourcapitaliststillcontinuestopayasbeforeonlyfiveshillingsasthevalueofaday’slabour—power。Hence，insteadof10hours，thelabourerneednowworkonly7½hours，inordertoreproducethisvalue。Hissurplus—labouris，therefore，increasedby2½hours，andthesurplus—valueheproducesgrowsfromone，intothreeshillings。Hence，thecapitalistwhoappliestheimprovedmethodofproduction，appropriatestosurplus—labouragreaterportionoftheworking—day，thantheothercapitalistsinthesametrade。Hedoesindividually，whatthewholebodyofcapitalistsengagedinproducingrelativesurplus—value，docollectively。
Ontheotherhand，however，thisextrasurplus—valuevanishes，sosoonasthenewmethodofproductionhasbecomegeneral，andhasconsequentlycausedthedifferencebetweentheindividualvalueofthecheapenedcommodityanditssocialvaluetovanish。Thelawofthedeterminationofvaluebylabour—time，alawwhichbringsunderitsswaytheindividualcapitalistwhoappliesthenewmethodofproduction，bycompellinghimtosellhisgoodsundertheirsocialvalue，thissamelaw，actingasacoercivelawofcompetition，forceshiscompetitorstoadoptthenewmethod。[5]Thegeneralrateofsurplus—valueis，therefore，ultimatelyaffectedbythewholeprocess，onlywhentheincreaseintheproductivenessoflabour，hasseizeduponthosebranchesofproductionthatareconnectedwith，andhascheapenedthosecommoditiesthatformpartof，thenecessarymeansofsubsistence，andarethereforeelementsofthevalueoflabour—power。
Thevalueofcommoditiesisininverseratiototheproductivenessoflabour。Andso，too，isthevalueoflabour—power，becauseitdependsonthevaluesofcommodities。Relativesurplus—valueis，onthecontrary，directlyproportionaltothatproductiveness。Itriseswithrisingandfallswithfallingproductiveness。Thevalueofmoneybeingassumedtobeconstant，anaveragesocialworking—dayof12hoursalwaysproducesthesamenewvalue，sixshillings，nomatterhowthissummaybeapportionedbetweensurplus—valueandwages。Butif，inconsequenceofincreasedproductiveness，thevalueofthenecessariesoflifefall，andthevalueofaday’slabour—powerbetherebyreducedfromfiveshillingstothree，thesurplus—valueincreasesfromoneshillingtothree。Tenhourswerenecessaryforthereproductionofthevalueofthelabour—power;nowonlysixarerequired。Fourhourshavebeensetfree，andcanbeannexedtothedomainofsurplus—labour。