ley ▁was ▁assigned ▁to ▁work ▁with ▁Dr . ▁A . J . ▁Mo yer . ▁Mo yer ▁suggested ▁adding ▁corn - ste ep ▁liqu or , ▁a ▁by - product ▁of ▁st arch ▁extra ction , ▁to ▁the ▁growth ▁medium . ▁With ▁this ▁and ▁other ▁subt le ▁changes , ▁such ▁as ▁using ▁la ct ose ▁in ▁place ▁of ▁gl uc ose , ▁they ▁were ▁able ▁to ▁push ▁up ▁yields ▁of ▁pen ic ill in ▁to ▁ 2 0 ▁units ▁per ▁mill il iter . ▁But ▁their ▁co operation ▁had ▁become ▁one - s ided . ▁He at ley ▁noted , ▁" Mo yer ▁had ▁begun ▁not ▁telling ▁me ▁what ▁he ▁was ▁doing ." ▁ ▁Fl ore y ▁returned ▁to ▁Oxford ▁that ▁September , ▁but ▁He at ley ▁stayed ▁on ▁in ▁Pe oria ▁until ▁December ; ▁then ▁for ▁the ▁next ▁six ▁months ▁he ▁worked ▁at ▁Mer ck ▁& ▁Co . ▁in ▁Rah way , ▁New ▁Jersey . ▁In ▁July ▁ 1 9 4 2 ▁he ▁returned ▁to ▁Oxford , ▁and ▁was ▁soon ▁to ▁learn ▁why ▁Mo yer ▁had ▁become ▁so ▁secret ive . ▁When ▁he ▁published ▁their ▁research ▁results , ▁he ▁omitted ▁He at ley ' s ▁name ▁from ▁the ▁paper , ▁despite ▁an ▁original ▁contract ▁which ▁st ip ulated ▁that ▁any ▁publications ▁should ▁be ▁joint ly ▁author ed . ▁Fif ty ▁years ▁on , ▁He at ley ▁conf essed ▁that ▁he ▁was ▁am used , ▁rather ▁than ▁ups et , ▁by ▁Mo yer ' s ▁dup licity . ▁Later ▁he ▁was ▁to ▁learn