▁this ▁requirement . ▁On ▁ 1 2 ▁February ▁ 1 9 4 1 , ▁Alexander ▁was ▁given ▁an ▁int ra ven ous ▁inf usion ▁of ▁ 1 6 0   m g ▁( 2 0 0 ▁units ) ▁of ▁pen ic ill in . ▁Within ▁ 2 4 ▁hours , ▁Alexander ' s ▁temperature ▁had ▁dropped , ▁his ▁app et ite ▁had ▁returned ▁and ▁the ▁in fection ▁had ▁begun ▁to ▁sub side . ▁However , ▁ow ing ▁to ▁the ▁inst ability ▁of ▁pen ic ill in ▁and ▁the ▁w art ime ▁restrictions ▁placed ▁on ▁Fl ore y ' s ▁labor atory , ▁only ▁a ▁small ▁quantity ▁was ▁available , ▁and ▁although ▁Fl ore y ▁and ▁colle agues ▁extracted ▁any ▁remaining ▁pen ic ill in ▁from ▁Alexander ' s ▁ur ine , ▁they ▁had ▁run ▁out ▁by ▁the ▁fifth ▁day ▁and ▁Alexander ▁died ▁a ▁month ▁later . ▁Fl ore y ▁and ▁his ▁team ▁there after ▁decided ▁to ▁work ▁only ▁on ▁sick ▁children , ▁who ▁did ▁not ▁need ▁such ▁large ▁dos es ▁of ▁pen ic ill in , ▁until ▁their ▁methods ▁of ▁production ▁improved . ▁ ▁Illinois ▁and ▁New ▁Jersey ▁Event ually ▁He at ley ▁and ▁Fl ore y ▁travel led ▁to ▁the ▁United ▁States ▁in ▁ 1 9 4 1 ▁because ▁they ▁wanted ▁to ▁produce ▁about ▁one ▁kil ogram ▁of ▁pure ▁pen ic ill in , ▁and ▁persu aded ▁a ▁labor atory ▁in ▁Pe oria , ▁Illinois , ▁to ▁develop ▁larger - scale ▁manufact uring ▁of ▁it . ▁In ▁Pe oria , ▁He at