Had you bothered to see the BBC link,you wouldnt have come up with the mamooth lie of Britishers using Opium for medical purposes. The BBC refrences clearly says,Opicum was the back bone of the Indian economy during British era.
As to Al-Biruni caming to doesnt in any way reduces what he has contributed. Your own excerpt says "in return he taught Greek and Arabic science".just because some one has vistied India doesnt mean his achivements are all because of this.What happened was intellectual exchange!!! Claiming otherwise will be puerile.
