▁tomb , ▁where ▁they ▁were ▁post hum ously ▁den ounced ▁and ▁burn ed ▁after ▁photograph s ▁were ▁taken ▁of ▁their ▁sk ull s . ▁Th ous ands ▁of ▁other ▁artifact s ▁were ▁also ▁destroyed . ▁ ▁In ▁ 1 9 9 7 , ▁China ' s ▁Ministry ▁of ▁Public ▁Security ▁published ▁a ▁book ▁on ▁the ▁history ▁of ▁drug ▁ab use . ▁It ▁stated ▁that ▁the ▁W an li ▁Emperor ' s ▁remains ▁had ▁been ▁exam ined ▁in ▁ 1 9 5 8 ▁and ▁found ▁to ▁contain ▁morph ine ▁resid ues ▁at ▁levels ▁which ▁indicate ▁that ▁he ▁had ▁been ▁a ▁heavy ▁and ▁habit ual ▁user ▁of ▁op ium . ▁▁ ▁Many ▁old ▁Chinese ▁history ▁books ▁on ▁the ▁M ing ▁dynast y ▁commonly ▁assert ▁that ▁W an li ’ s ▁regime ▁caused ▁the ▁rapid ▁down fall ▁of ▁the ▁dynast y . ▁However , ▁there ▁are ▁different ▁opinions ▁as ▁to ▁why ▁W an li ▁was ▁neglect ful ▁for ▁a ▁long ▁time . ▁Some ▁histor ians ▁claim ▁that ▁he ▁suffered ▁from ▁severe ▁de pression ▁after ▁Z hang ’ s ▁death ▁in ▁ 1 5 8 2 , ▁that ▁he ▁was ▁a ▁heavy ▁and ▁habit ual ▁user ▁of ▁op ium ▁and ▁that ▁he ▁suffered ▁from ▁a ▁rare ▁mal ady ▁on ▁his ▁back ▁and ▁leg , ▁so ▁that ▁he ▁was ▁unable ▁to ▁walk ▁without ▁help . ▁When ▁his ▁tomb ▁was ▁exc av ated ▁in ▁ 1 9 5 8 , ▁his ▁body ▁was ▁restored ▁and ▁histor ians ▁found ▁out ▁that ▁W an li ’ s ▁upper ▁body ▁was ▁notice