. ▁His ▁spec im ens ▁were ▁prepared ▁primarily ▁with ▁in jections ▁of ▁w ax - cont aining ▁flu ids ▁into ▁body ▁cav ities , ▁creating ▁relatively ▁dur able ▁shapes . ▁ ▁The ▁C rypt s ▁of ▁Lie ber k ü hn ▁( int est inal ▁g lands ) ▁are ▁named ▁for ▁him ; ▁he ▁first ▁described ▁these ▁in ▁detail ▁in ▁De ▁fab rica ▁et ▁action e ▁vol lor um ▁int est in orum ▁ten ui um ▁hom in is , ▁in ▁ 1 7 4 5 . ▁Bey ond ▁this , ▁Lie ber k ü hn ▁produced ▁optical ▁instruments , ▁further ▁developing ▁the ▁light ▁mic ros cope , ▁which ▁he ▁had ▁seen ▁for ▁the ▁first ▁time ▁in ▁Amsterdam . ▁His ▁custom ▁micro scop es ▁for ▁studying ▁blood ▁vessels ▁were ▁called ▁" W under gl ä ser ", ▁‘ w onder - glass es ’ ▁by ▁his ▁contempor aries . ▁▁ ▁In ▁ 1 7 5 5 , ▁Lie ber k ü hn ▁was ▁elected ▁a ▁foreign ▁member ▁of ▁the ▁Royal ▁Swedish ▁Academy ▁of ▁Sciences . ▁ ▁See ▁also ▁ ▁C rypt s ▁of ▁Lie ber k ü hn ▁ ▁External ▁links ▁ ▁S ources ▁▁ ▁Category : 1 8 th - century ▁German ▁phys icians ▁Category : M embers ▁of ▁the ▁Royal ▁Swedish ▁Academy ▁of ▁Sciences ▁Category : Phys icians ▁from ▁Berlin ▁Category : 1 7 1 1 ▁birth s ▁Category : 1 7 5 6 ▁death s ▁Category : F ell ows ▁of ▁the ▁Royal ▁Society <0x0A> </s> ▁Rus ht own ▁is