▁his ▁works ▁are ▁of ▁pre - em inent ▁value ▁in ▁the ▁field ▁of ▁Indian ▁and ▁compar ative ▁phil ology . ▁ ▁His ▁first ▁great ▁work ▁was ▁an ▁edition ▁of ▁the ▁S ansk rit ▁grammar ▁of ▁Pan ini , ▁, ▁with ▁a ▁German ▁comment ary , ▁under ▁the ▁title ▁A cht ▁Bü cher ▁gram mat ischer ▁Reg eln ▁( B onn , ▁ 1 8 3 9 – 1 8 4 0 ). ▁This ▁was ▁in ▁reality ▁a ▁criticism ▁of ▁Franz ▁Bo pp ' s ▁phil ological ▁methods . ▁ ▁This ▁work ▁was ▁followed ▁by : ▁V op ade vas ▁Gram mat ik ▁( Saint ▁Petersburg , ▁ 1 8 4 7 ) ▁Über ▁die ▁Sprache ▁der ▁Jak uten ▁( Saint ▁Petersburg , ▁ 1 8 5 1 ) ▁Ind ische ▁S prü che , ▁a ▁series ▁of ▁S ansk rit ▁ap othe g ms ▁and ▁pro verb ial ▁vers es ▁( 2 nd ▁ed . ▁in ▁ 3 ▁parts , ▁Saint ▁Petersburg , ▁ 1 8 7 0 – 1 8 7 3 , ▁to ▁which ▁an ▁index ▁was ▁published ▁by ▁Bla u , ▁Leipzig , ▁ 1 8 9 3 ) ▁a ▁critical ▁exam ination ▁and ▁translation ▁of ▁Ch and og ya - up an ish ad ▁( Saint ▁Petersburg , ▁ 1 8 8 9 ) ▁a ▁translation ▁of ▁B ri had - A ran y aka - up an ish ad ▁( Saint ▁Petersburg , ▁ 1 8 8 9 ) ▁ ▁His ▁mag num ▁op us ▁was ▁his ▁great