▁her b iv ore ▁of ▁the ▁North ▁American ▁continent ▁for ▁over ▁ten ▁thousand ▁years , ▁and ▁is ▁a ▁direct ▁ancest or ▁of ▁the ▁living ▁American ▁b ison . ▁ ▁Other ▁scientific ▁fields ▁Le id y ▁was ▁also ▁a ▁ren owned ▁par as it ologist , ▁and ▁determined ▁as ▁early ▁as ▁ 1 8 4 6 ▁that ▁tr ich inos is ▁was ▁caused ▁by ▁a ▁par as ite ▁in ▁under co oked ▁meat . ▁He ▁was ▁also ▁a ▁pione ering ▁proto zo ologist , ▁publishing ▁F resh - water ▁Rh iz op ods ▁of ▁North ▁America ▁in ▁ 1 8 7 9 ▁– ▁a ▁work ▁that ▁is ▁still ▁referenced ▁today . ▁ ▁Le id y ▁collected ▁g ems ▁as ▁well ▁as ▁foss ils , ▁and ▁don ated ▁his ▁important ▁collection ▁of ▁the ▁former ▁to ▁the ▁Smith son ian ▁before ▁he ▁died . ▁At ▁Sw arth more , ▁he ▁also ▁taught ▁a ▁class ▁on ▁min eral ogy ▁and ▁ge ology . ▁ ▁For ens ic ▁innov ator ▁In ▁ 1 8 4 6 , ▁Le id y ▁became ▁the ▁first ▁person ▁ever ▁to ▁use ▁a ▁mic ros cope ▁to ▁solve ▁a ▁murder ▁mystery . ▁A ▁man ▁accused ▁of ▁killing ▁a ▁Philadelphia ▁far mer ▁had ▁blood ▁on ▁his ▁clothes ▁and ▁h atch et . ▁The ▁suspect ▁claimed ▁the ▁blood ▁was ▁from ▁ch ick ens ▁he ▁had ▁been ▁sla ugh ter ing . ▁Using ▁his ▁mic ros cope , ▁Le id y ▁found ▁no ▁nuc lei ▁in ▁these ▁er yth ro cy tes ▁( human ▁er yth